noun:

• one sheet; one page; one leaf
• one block of tofu; one serving (in a restaurant)
• one long and narrow thing (e.g. guns, scissors, spades, hoes, inksticks, palanquins, candles, jinrikishas, shamisen, oars, etc.) - also written as 一挺, 一梃
• one cho (unit of distance, 109.09 m)
• one game; one task

adverbial noun:

• well then; come then