used as an exclamation of surprise, indignation, etc; also used dismissively and as an expression of resignation UK,1887
[Y]our visibility in the rear-view mirror, through two sets of thick, tinted glass, is reduced almost to zero. But what the heck, because you pretty much know already what’s behind you: people making “wanker” gestures[.] — TheGuardian, 22 May 2002