iff

Mathematics.

if and only if.

Nearby words

ifa, ifad, ifalp, ifc, ife, iff, iffen, iffy, ifn, ifni, ifp

Definition for iff (2 of 2)

IFF

Military.

Identification, Friend or Foe: a system of transmitters and transponders that uses coded signals to distinguish between friendly and hostile aircraft.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for iff

The IFF, however, is not exactly an organization to be proud of.
The Real Jersey Dictionary, Vol. 2|Jaimie Etkin|October 21, 2010|DAILY BEAST
The bottom dropped out of the market for confidence in the integrity of Mr. Iff and conceit in the perspicacity of Mr. Staff.
The Bandbox|Louis Joseph Vance
“Give you twenty-five if you get away from the dock within five minutes,” Iff told the boatbuilder directly.
The Bandbox|Louis Joseph Vance
Iff swung out of sight into the back room as Staff went to and opened the hall-door.
The Bandbox|Louis Joseph Vance

Round it were grouped in various attitudes of dejection sundry other pieces of travelling-gear and Mr. Iff.
The Bandbox|Louis Joseph Vance
It was, in fact, the bandbox which had first fixed the interest of Mr. Iff.
The Bandbox|Louis Joseph Vance

British Dictionary definitions for iff (1 of 2)

iff

/ (ɪf) /

conjunction

logic a shortened form of if and only if : it indicates that the two sentences so connected are necessary and sufficient conditions for one another. Usually iff is used for equivalence in the metalanguage, rather than as the biconditional in the object language

British Dictionary definitions for iff (2 of 2)

IFF

/ military /

abbreviation for

Identification, Friend or Foe: a system using radar transmissions to which equipment carried by friendly forces automatically responds with a precoded signal

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012