First Known Use: 1955
Dictionary
iff
conjunction \ˈif-ən(d)-ˈōn-lē-ˌif; ˈif, sometimes read with a prolonged f\
Definition of IFF
: if and only if <two figures are congruent iff one can be placed over the other so that they coincide>
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Origin of IFF
alteration of 1if
IFF
abbreviation
Definition of IFF
identification, friend or foe
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