if not
Adverb
Meaning
perhaps; indicating possibility of being more remarkable (greater or better or sooner) than
Source: WordNetSynonyms
Examples
What do we live for, if not to make life less difficult for each other?
Love is never lost. If not reciprocated, it will flow back and soften and purify the heart.
I could see that, if not actually disgruntled, he was far from being gruntled.
If not for fear, sin would be sweet.
Ink, if not used, will dry up.
Dear physic always does good, if not to the patient, at least to the apothecary.