adjective

showing smug or uncritical satisfaction with oneself or one’s achievements.

you can’t afford to be complacent about security

smug,self-satisfied,pleased with oneself,proud of oneself,self-approving,self-congratulatory,self-admiring,self-regarding,gloating,triumphant,proud,pleased,gratified,satisfied,content,contented,careless,slack,lax,lazy,I’m-all-right-Jack,wisenheimer,shit-eating