Meaning of -ER in English

-ER

[-er] adj suffix or adv suffix [ME -er, -ere, -re, fr. OE -ra (in adjectives), -or (in adverbs); akin to OHG -iro, adj. compar. suffix, L -ior, Gk -ion]--used to form the comparative degree of adjectives and adverbs of one syllable "hotter" "drier" and of some adjectives and adverbs of two syllables "completer" and sometimes of longer ones "beautifuler"

[2]-er also -ier or -yer n suffix [ME -er, -ere, -ier, -iere; partly fr. OE -ere (fr. L -arius); partly fr. OF -ier, -iere, fr. L -arius, -aria, -arium -ary; partly fr. MF -ere, fr. L -ator -or--more at -ary, -or] 1 a: person occupationally connected with "hatter" "furrier" "lawyer" b: person or thing belonging to or associated with "header" "old-timer" c: native of: resident of "cottager" "New Yorker" d: one that has "three-decker" e: one that produces or yields "porker"

2. a: one that does or performs (a specified action) "reporter"--sometimes added to both elements of a compound "builder-upper" b: one that is a suitable object of (a specified action) "broiler"

3: one that is "foreigner"--in all senses -yer in a few words after w, -ier in a few other words, otherwise -er

Merriam-Webster English vocab.      Английский словарь Merriam Webster.