isabnormal: Meaning and Definition of

is•ab•nor•mal

Pronunciation: (ī"sab-nôr'mul), [key]
— n. Meteorol.
  1. a line on a map or chart connecting points having an equal deviation from the normal value of some meteorological quantity, as temperature.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.