Possible Duplicate:
Is there a term for words that have a single meaning or are only used in a single context?

I don't think I've ever heard the word "crossbones" outside of the phrase "skull and crossbones." I'll call it a unitasker word — a word that is used within a single phrase the vast majority of the time.

Is there a more official term for a unitasker word?

Are there other examples?

marked as duplicate by Uticensis, RegDwigнt May 18 '11 at 8:50

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Browse other questions tagged or ask your own question.