Why not "messager"? Or "messenge"?
E.g. Why don't we say:
Send me a messenge on instant messager.
Why not "messager"? Or "messenge"?
E.g. Why don't we say:
Send me a messenge on instant messager.
Generally the phenomenon is called the intrusive consonant.
Messenger shows us a case of "intrusive N" or "parasitic N." Nasal consonants are often used in this way, but not exclusively nasals.
From http://www.etymonline.com/index.php?term=messenger
With parasitic -n- inserted by c. 1300 for no apparent reason except that people liked to say it that way (compare passenger, harbinger, scavenger).
Please see the similar etymology for passage --> passenger.
http://www.etymonline.com/index.php?term=passenger
The -n- was added early 15c. (compare messenger, harbinger, scavenger, porringer).
More examples can be found at https://apgalton.wordpress.com/2014/04/23/intrusive-n/ below:
This insertion of -n- (or -ng-) seems to happen quite naturally in English. As far as I can see, it is particularly prone to happen in a weakly stressed second syllable of a three-syllable word....
Here are some examples where forms with the infixed -n- have become standard:
Nightingale, from Old English nihtegala – compare the German Nachtigall.
Celandine, ultimately from Greek khelidonion, a derivative of khelidon, a swallow.
Popinjay, an old word for a parrot, from Spanish papagayo.
Messenger, from Old French messager – compare message.
Passenger, from Old French passager – compare passage.
Harbinger, from Old French herbergere.
An interesting reference is Intrusive Nasals in English by Louise Pound Modern Language Notes Vol. 30, No. 2 (Feb., 1915), pp. 45-47 here: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0ahUKEwie6K3j2cPOAhVTySYKHVMuAOsQFggqMAI&url=https%3A%2F%2Fwww.jstor.org%2Fstable%2F2916901&usg=AFQjCNGxZENNmAwlRBYxPT9LIE0u7Ztovg&sig2=kTD8e9Eunt8FBYVL2Ovg0Q&bvm=bv.129422649,d.dmo
Be aware that the development of the English language came about arbitrarily. There may be no rhyme or reason involved in the acceptance of a spelling, however in the case of "messenger" the "n" is present because when pronounced correctly there is an "n" sound at that location in the word.