(computing, informal) The rule that a database, a user interface, etc. should allow for either zero, one, or an indefinite number of an entity.

(grammar) The use of the "to" infinitive form of a verb in answer to the implied question "why?".

(medicine) Synonym of acute necrotizing ulcerative gingivitis

With respect to, or by means of, inference

plural of inferior colliculus

plural of inferior vena cava

plural of infinite recursion

plural of infield fly

(baseball) A batted ball which is in play and subject to the infield fly rule.

(baseball) A rule providing that a fair fly ball hit with a force play at third base, which is deemed catchable by an umpire, be ruled an out irrespective of the fielder's play, eliminating the force play at all bases.