only if

1. 1.

   never except when

   “call me only if your cold gets worse”

   Synonymsonlyonly when

Questions about only if

What does only if mean?

only if means "never except when".

What is another word for only if?

Close synonyms include only, only when. Each sense on this page lists its own synonyms, because a word with several meanings rarely has one substitute that works for all of them.

Is only if a common word?

only if is banded "Uncommon" — turns up in careful writing rather than conversation. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.