(business) one on one meeting between an employee and a superior

January

(Internet slang) first comment; (interjection) first!

(informal, chiefly in the negative) the slightest amount (in reference to one's knowledge, thought, etc.) / Used other than figuratively or idiomatically: see 一, ミリ.

Alternative spelling of 一輪車 (“unicycle”)

Synonym of チアミン (chiamin, “thiamine”); vitamin B1

(informal) "not knowing even a millimeter": completely ignorant in regards to something