1. conjunction /ɪf/
a) Supposing that, assuming that, in the circumstances that;
If it rains, I will get wet.
b) Supposing that;
Id prefer it if you took your shoes off.
2. noun /ɪf/
Sir Fran. Nay, but Chargy, if——— ¶ Miran. Nay, Gardy, no Ifs.——Have I refusd three northern lords, two British peers, and half a score knights, to have put in your Ifs?
Wikipedia foundation.