unbidden
/ˌʌnˈbɪdən/adjective
1- without having been commanded or invited未奉命的; 未被邀请的：
unbidden guests.
不速之客。
1.1
- (especially of a thought or feeling) arising without conscious effort（尤指思想, 情感）自发的：
unbidden tears came to his eyes.
他情不自禁地流泪。