neologism

Definition

A newly coined word or expression that has not yet become part of standard language. It may eventually be accepted into common usage.

日本語 標準語にまだ取り入れられていない新しく造られた言葉または表現; いつのまにか一般的な使用に受け入れられる

Example

"The term 'selfie' began as a neologism before gaining widespread recognition."