any of a family (Sialidae) of weak-flying neuropteran
insects found near running
water and having aquatic larvae that are often used as fishing bait
Webster’s New World College Dictionary, 4th Edition. Copyright © 2010 by
Houghton Mifflin Harcourt. All rights reserved.
Word origin of 'alderfly' alder
: prob. so called because they inhabit alders along shore