1. placet - Noun
2. placet - Interjection
A vote of assent, as of the governing body of a university, of an ecclesiastical council, etc.
The assent of the civil power to the promulgation of an ecclesiastical ordinance.
Source: Webster's dictionaryThe final vote, with a choice only between placet and non placet, was taken on 18 July 1870, with 433 votes in favour and only 2 against defining as a dogma the infallibility of the pope when speaking ex cathedra. Source: Internet