the GNU version of the Collaborative International Dictionary of English
n. Departure from the ordinary type; irregularity; monstrosity.
The Century Dictionary and Cyclopedia
n. Irregularity; deformity; abnormality.
Word Usage
"The reason for it is this: that fair hair and blue eyes are a deviation from the type and almost constitute an abnormity, analogous to white mice, or at any rate white horses."