Answer: ifever

AnswerCrossword Clue
IFEVERWords suggesting a rare occurrence
IFEVER"In the unlikely event that ..."
IFEVERShould it happen that
IFEVER".. I Would Leave You"
IFEVERIn song, words before "a wiz there was"
IFEVERAssuming it'll happen at all
IFEVERAssuming, hypothetically
IFEVER"Should that come to pass"
IFEVERAssuming it's even possible
IFEVERAssuming it will happen at all
IFEVERIntensifier for "seldom"
IFEVERPerhaps not at all
IFEVERShould that happen