一階(いっかい)

いっかい
noun
first floor; ground floor
1. first floor; ground floor
The lowest above-ground level of a building. Japanese floor numbering starts at 一階(いっかい) for the level you enter from the street, matching American "first floor" and British "ground floor."
一階(いっかい)で待(ま)っています。
I'll be waiting on the first floor.
受付(うけつけ)は一階(いっかい)にあります。
Reception is on the first floor.
一階(いっかい)にはレストランと書店(しょてん)が入(はい)っている。
The first floor has a restaurant and a bookstore in it.

階(かい) is the counter for floors of a building. With 一(いち) it undergoes sound change to いっかい. The kanji 階(かい) also appears in 階段(かいだん) (stairs) and 階下(かいか) (downstairs).

COMMON COLLOCATIONS:

  • 一階(いっかい)に降(お)りる: to go down to the first floor
  • 一階(いっかい)部分(ぶぶん): first-floor section
  • 一階(いっかい)建(だ)て: one-storey (building)

RELATED FORMS:

  • 二階(にかい): second floor
  • 地下(ちか)一階(いっかい): first basement level (B1)
  • 最(さい)上階(じょうかい): top floor

HOMOPHONE:
一回(いっかい) "one time" sounds identical but uses 回(かい) (counter for times). Context normally distinguishes them.

general
Added 2026.5.13 12:10
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