iff

1 of 2

conjunction

ˈif-ᵊn(d)-ˈōn-lē-ˌif How to pronounce iff (audio)
ˈif,
sometimes read with a prolonged
How to pronounce iff (audio)
: if and only if
two figures are congruent iff one can be placed over the other so that they coincide
used in logic and mathematics

IFF

2 of 2

abbreviation

identification, friend or foe

Word History

Etymology

Conjunction

alteration of if entry 1

First Known Use

Conjunction

1955, in the meaning defined above

Time Traveler
The first known use of iff was in 1955

Dictionary Entries Near iff

Cite this Entry

“Iff.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/iff. Accessed 9 Oct. 2024.

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