IPA: /kəmˈpleɪsəntli/
KK: /kəmˈpleɪsəntli/
In a way that shows too much satisfaction with oneself or one's achievements, often without awareness of potential dangers or problems.
She smiled complacently after receiving praise for her work, unaware of the challenges ahead.
Complacently → It is formed from "com-" (meaning together or with) and "placere" (meaning to please). The word describes a state of being pleased with oneself, often without awareness of potential dangers or deficiencies.
Think of being 'pleased' ('placere') with yourself 'together' ('com-') — that's why complacently means being self-satisfied.