A loanword from English 'wild' used as a na-adjective to describe something untamed, rugged, or boldly showy; also used for rough or uncivilized behaviour or style.
彼の髪型はワイルドで目立つ。
His hairstyle is wild and eye‑catching.
山でのキャンプはワイルドな体験だった。
Camping in the mountains was a wild experience.
あの俳優はワイルドな役柄がよく似合う。
That actor suits wild (rough/bold) roles well.