ab·nor·mal (āb-nôr'məl) adj. Not typical, usual, or regular; not normal; deviant.
[Alteration (influenced by ab-1) of obsolete anormal, from Medieval Latin anormālis, blend of Late Latin abnormis (Latin ab-, away from; see ab-1 + Latin norma, rule; see gnō- in Indo-European roots) and anōmalus; see anomalous.] ab·nor'mal·ly adv.
1835, replaced older anormal and abnormous (1742) under infl. of L. abnormis "deviating from a rule," from ab- "off, away from" + norma "rule" (see norm). The older forms were via O.Fr. anormal (13c.), from M.L. anormalos, from Gk. anomalos, from an- "not" + homalos, from homos "same." The Gk. word influenced in L. by association with norma.
Main Entry: 1ab·nor·mal Pronunciation: (')ab-'nor-m&l Function: adjective 1: deviating from the normal or average;especially: departing from the usual or accepted standards of social behavior 2: characterized by mental retardation or disorder —ab·nor·mal·ly/-m&-lE/adverb
Main Entry: 2abnormal Function: noun : an abnormal person