well-versed in usages or practices of the court or military households

(linguistics) special reading of kanji; especially, reading given names using the 音読み (on'yomi)

everything

(colloquial) current boyfriend

(slang) Alternative form of 彼氏 (kareshi, “boyfriend”)

everyone, one and all

(education) The 1,026 kanji taught in primary school; a subset of 常用漢字 (じょうようかんじ, jōyō kanji)

a research student (i.e. a visiting or non-matriculating graduate student) / a researcher

researcher

a laboratory