What does abnormal mean?
The definition of abnormal
Ab*nor”mal, a.
Etym: [For earlier anormal.F. anormal, LL. anormalus for anomalus, Gr. abnormis. See Anomalous, Abnormous, Anormal.]

Not conformed to rule or system; deviating from the type; anomalous; irregular. “That deviating from the type; anomalous; irregular. ” Froude.