Dictionary.net

• Having the anterior lobes of the foot so modified as to form a pair of winglike swimming organs; - said of the pteropod mollusks.

2010 - New Age Dictionary Database
By Oddity Software

• Having the anterior lobes of the foot so modified as to form a pair of winglike swimming organs; - said of the pteropod mollusks.

1913 - Webster's Revised Unabridged Dictionary
By Noah Webster.