var. of -er 1, usually in nouns designating trades: collier; clothier; furrier; glazier.
a noun suffix occurring mainly in loanwords from French, often simply a spelling variant of -eer, with which it is etymologically identical (bombardier; brigadier; financier; grenadier); it is also found on an older and semantically more diverse group of loanwords that have stress on the initial syllable (barrier; courier; courtier; terrier). Recent loanwords from French may maintain the modern French pronunciation with loss of the final r sound (croupier; dossier; hotelier).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.