"obstinate in refusal," 1610s, from Latin recusantem (nominative recusans) "refusing to obey," present participle of recusare "make an objection against; decline, refuse, reject; be reluctant to" (see recuse).

Earlier as a noun in English history, specifically of those who refused to attend divine service in Anglican churches (1550s), a punishable offense, enforcement of which fell heavily on Roman Catholics. The original use of the adjective also is in reference to this.