conj. & n.
--conj.
1. introducing a conditional clause: a on the condition or supposition that; in the event that (if he comes I will tell him; if you are tired we will rest). b (with past tense) implying that the condition is not fulfilled (if I were you; if I knew I would say).
2 even though (I'll finish it, if it takes me all day).
3 whenever (if I am not sure I ask).
4 whether (see if you can find it).
5 a expressing wish or surprise (if I could just try!; if it isn't my old hat!). b expressing a request (if you wouldn't mind opening the door?).
6 with implied reservation, and perhaps not (very rarely if at all).
7 (with reduction of the protasis to its significant word) if there is or it is etc. (took little if any).
8 despite being (a useful if cumbersome device).
--n. a condition or supposition (too many ifs about it).
Phrases and idioms:
if only
1. even if for no other reason than (I'll come if only to see her).
2 (often ellipt.) an expression of regret (if only I had thought of it; if only I could swim!). if so if that is the case.
Etymology: OE gif