Synonyms of buttoned up

Verb

1. close up, clam up, dummy up, shut up, belt up, button up, be quiet, keep mum

usage: refuse to talk or stop talking; fall silent; "The children shut up when their father approached"

Adjective

1. buttoned-up, taciturn (vs. voluble)

usage: (British colloquial) not inclined to conversation

2. buttoned-up, conservative (vs. liberal)

usage: conservative in professional manner; "employers are looking for buttoned-up types"