if not

1. 1.

   perhaps; indicating possibility of being more remarkable (greater or better or sooner) than

   “will yield 10% if not more”

   “pretty if not actually beautiful”

   “let's meet tonight if not sooner”

Questions about if not

What does if not mean?

if not means "perhaps; indicating possibility of being more remarkable (greater or better or sooner) than".

Is if not a common word?

if not 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.