ˈif-ᵊn(d)-ˈōn-lē-ˌif 
ˈif,
sometimes read with a prolonged
f
: 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
identification, friend or foe
Cite this Entry
“Iff.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/iff. Accessed 18 Jul. 2025.
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