Fossil word is a term used in linguistics to describe a word that is no longer in everyday use but is still preserved in certain expressions or phrases.

The pillow word is a common literary device used in Japanese waka poetry.

She used several pillow words in her speech.

The Lyndon words are difficult to pronounce.

Lyndon is a talented musician.

He always uses bug-words to annoy his sister.

The actions of the team were commendable.

The nonsense words were difficult to understand.

The children were playing with their babble-words.

The children were playing with their babble words.