1.
one lap, one circuit, one round
Going around something once; making a complete circuit.
公園を一周する。
I go around the park once.
グラウンドを一周走る。
I run one lap around the field.
世界一周旅行に出かける。
I set off on a trip around the world.
2.
one year anniversary
The completion of one year since an event.
開店一周年を祝う。
We celebrate the first anniversary of opening.
結婚一周年おめでとう。
Congratulations on your first wedding anniversary.
祖父の一周忌を迎える。
We observe the first anniversary of grandfather's death.
一周 has two main uses.
SENSE 1 - ONE LAP/CIRCUIT:
- 一周する: to go around once
- 世界一周: around the world
- 日本一周: around Japan
SENSE 2 - FIRST ANNIVERSARY:
- 一周年: first anniversary
- 一周忌: first death anniversary (Buddhist term)
RELATED COUNTERS:
- 二周: two laps / second anniversary
- 三周: three laps / third anniversary