Meaning
The kanji 周 (shū) is a versatile and fundamental character, primarily conveying the idea of "around," "circumference," "perimeter," or a "cycle." It is also commonly used as a counter for weeks, making it essential for discussing time. Think of something encircling another object, a complete circuit, or the boundary of an area; these are the core meanings associated with 周.
Its origin is quite illustrative. 周 is an ideograph that visually represents a field or territory (originally depicted by something like 田, now simplified) enclosed by a boundary or a fence (the outer 冂, an enclosure radical). This visual structure immediately suggests the concept of "surrounding" or "periphery." Over time, the inner component simplified to what looks like 士 (scholar/samurai), but its function in 周 is primarily phonetic or a simplification of an earlier form that represented the contents within an enclosure. The outer enclosure, 冂 (kei-gamae), strongly reinforces the idea of something encompassing or going around.
Thus, the visual shape directly connects to its meaning: the outer box-like component 冂 clearly outlines an "enclosure" or a path "around" something. Meanwhile, the inner part denotes what is being surrounded or the central point of reference. This combination naturally leads to meanings such as "circumference," "periphery," and, by extension, a complete "cycle" or a "week."
This kanji has 8 strokes and is taught in Grade 6 of Japanese elementary school, making it an essential character to master for JLPT N2 and beyond.
Readings
On'yomi (音読み) — Chinese-derived readings
The primary on'yomi for 周 is シュウ (SHŪ). This reading is very common and appears in a wide array of compound words, particularly those related to time, cycles, and spatial concepts of surrounding or encompassing.
- 周囲 (shūi) — surroundings, perimeter, environs. This refers to the area or boundary encircling something. For example, 学校の周囲には森がある (Gakkō no shūi ni wa mori ga aru) means "There's a forest around the school."
- 一週間 (isshūkan) — one week. This is a very common time expression. For example, to say "I'm going on a trip in one week," you would use 一週間後に旅行に行く (Isshūkan-go ni ryokō ni iku).
- 周期 (shūki) — cycle, period. It refers to a recurring pattern or interval, often used in scientific or systematic contexts. For instance, 月の周期 (tsuki no shūki) is "the lunar cycle."
- 円周 (enshū) — circumference (of a circle). This is a precise mathematical term. For instance, 円周の長さ (enshū no nagasa) means "the length of the circumference."
Kun'yomi (訓読み) — Native Japanese readings
周 has several important kun'yomi readings that allow it to function as native Japanese words, often with subtle differences in nuance:
- まわ.る (mawa.ru) — This means "to go around," "to turn," or "to circulate." It is often used with the particle の to indicate movement around something. For example, 湖の周りを散歩する (mizuumi no mawari o sanpo suru) means "to take a walk around the lake."
- まわ.り (mawa.ri) — This is the noun form, meaning "the area around," "surroundings," or "circumference." It refers to the physical vicinity. For example, 駅の周りにはたくさんの店がある (eki no mawari ni wa takusan no mise ga aru) means "There are many shops around the station."
- めぐ.る (megu.ru) — While めぐる is listed as a kun'yomi for 周, it is far less common than 巡 (めぐる), which predominantly carries the meaning of "to go around," "to revolve," or "to tour." In modern Japanese, when 周 implies movement around something, the reading まわる (mawa.ru) is overwhelmingly preferred. Thus, for practical purposes, focus on 巡 (めぐる) for dynamic touring/revolving and 周る (まわる) for general "going around."
- めぐ.らす (megu.rasu) — This is the transitive form, meaning "to turn around," "to rotate," or "to put around." It often carries a metaphorical sense, especially in phrases like 知恵を周めぐらす (chie o megurasu), which means "to rack one's brains" or "to ponder deeply." Another common example is 視線を周めぐらす (shisen o megurasu), meaning "to cast one's eyes around."
Common Words & Compounds
Here are some common words and compounds featuring 周, grouped by their themes to help you remember their usage.
Time & Cycles
- 一週間 (isshūkan) — one week. This is the standard term for a seven-day period.
- 今週 (konshū) — this week. An essential term for daily scheduling!
- 来週 (raishū) — next week. Used when planning future events.
- 先週 (senshū) — last week. Used when referring to past events.
- 毎週 (maishū) — every week. Indicates something happens regularly each week.
- 周期 (shūki) — cycle, period. Refers to recurring patterns, from scientific cycles to natural phenomena.
Circumference & Area
- 周囲 (shūi) — surroundings, perimeter, environs. Denotes the area or boundary surrounding something.
- 円周 (enshū) — circumference (of a circle). A precise mathematical term used in geometry and physics.
- 周遊 (shūyū) — a tour, a round trip. Often used for travel, like 世界一周周遊 (sekai isshū shūyū) for a "world tour."
- 周波数 (shūhasū) — frequency (e.g., of radio waves). A technical term describing how often something cycles.
Around / Complete
- 周辺 (shūhen) — vicinity, surrounding area. Similar to 周囲 (shūi), but often implies a slightly broader or less precisely defined area. For example, 駅の周辺 (eki no shūhen) means "the area around the station."
- 一周 (isshū) — one lap, one round, one turn around. Used for completing a circuit, such as in track and field races or for going around an island.
- 周到 (shūtō) — thorough, meticulous, careful. Here, 周 conveys the sense of being 'complete' or 'all-encompassing' in preparations or actions, leading to the meaning 'thorough.' For instance, 周到な準備 (shūtō na junbi) means "thorough preparations."
Example Sentences
今週は仕事がとても忙しいです。
Konshū wa shigoto ga totemo isogashii desu.
This week, work is very busy.
公園の周りをジョギングしました。
Kōen no mawari o jogingu shimashita.
I jogged around the park.
地球は太陽の周りを回っています。
Chikyū wa taiyō no mawari o mawatteimasu.
The Earth revolves around the sun.
部屋の周囲には本棚が並べられています。
Heya no shūi ni wa hondana ga naraberareteimasu.
Bookshelves are arranged around the perimeter of the room.
来週までにこのレポートを完成させなければなりません。
Raishū made ni kono repōto o kansei sasenakereba narimasen.
I must complete this report by next week.
町の周辺は最近ずいぶん開発されました。
Machi no shūhen wa saikin zuibun kaihatsu saremashita.
The area around the town has been quite developed recently.
彼は知恵を周らして、難問を解決しました。
Kare wa chie o megurashite, nanmon o kaiketsu shimashita.
He racked his brains and solved the difficult problem.
動物の生態系の研究は、季節の周期に合わせて行われます。
Dōbutsu no seitaikei no kenkyū wa, kisetsu no shūki ni awasete okonawaremasu.
Research into animal ecosystems is conducted according to seasonal cycles.
子供たちは先生の周りに集まって、お話を聞きました。
Kodomotachi wa sensei no mawari ni atsumatte, ohanashi o kikimashita.
The children gathered around the teacher and listened to the story.
湖の円周は約10キロメートルです。
Mizuumi no enshū wa yaku jū kiromētoru desu.
The circumference of the lake is approximately 10 kilometers.
Memory Tip
To remember 周, let's break it down into its components. The outer box-like structure is 冂 (kei-gamae), an enclosure radical. Imagine this as a large fence or a boundary. Inside this enclosure, we see 士 (shi), which can represent a scholar or a samurai. You can visualize a diligent scholar (士) diligently pacing around (冂) the perimeter of a garden while pondering complex ideas. This image effectively brings together the ideas of "around" and "enclosure."
Alternatively, think of "士" as a simplified "土" (earth) within an "enclosure." This symbolizes a plot of land or territory that you walk "around" to define its "circumference." The key visual is the enclosing shape, which strongly suggests movement or position around something, directly connecting to its core meanings of circumference and surrounding.