(a)行为的主动者，做某事的人，如：singer 歌唱家；leader 领袖；dancer 跳舞者；fighter 战士；reader 读者；truner 车工；writer 作者，作家。
(b)与某事物有关的人，如：hatter 帽商，制帽工人；teenager （十三至十九岁的青年）；banker 银行家；tinner 锡匠；miler 一英里赛跑运动员。
(c)属于某国某地区的人，如：United Stateser 美国人；Britisher 英国人；New Yorker 纽约人；Londoner 伦敦人；Thailander 泰国人；inlander 内地人；villager 村民。
washer 洗衣机；fiver 五元钞票；lighter 打火机；tenner 十元钞票；heater 加热器；silencer 消音器；cutter 切削器；woodpecker 啄木鸟;boiler 煮器；creeper 爬行动物。
norther 强北风；souther 强南风；northwester 强西北风；southeaster 强东南风；
表示反复动作、连续动作及拟声动作，如：waver 来加摆动；mutter 喃喃自语；chatter 喋喋不休；clatter 作卡嗒声；stutter 结舌，口吃；patter 发嗒嗒声；batter连打；whisper 低语，作沙沙声。
表示比较级“更…”，如：greater 更大；faster 更快；warmer 更暖；earlier 更早；happier 更快乐；harder 更努力。
English agent noun ending, corresponding to Latin -or. In native words it represents Old English -ere (Old Northumbrian also -are) "man who has to do with," from West Germanic *-ari (cf. German -er, Swedish
-are, Danish -ere), from Proto-Germanic *-arjoz. Some believe this root is identical with, and perhaps a borrowing of, Latin -arius.
In words of Latin origin, verbs derived from pp. stems of Latin ones (including most verbs in -ate) usually take the Latin ending -or, as do Latin verbs that passed through French (e.g. governor), but there
are many exceptions (eraser, laborer, promoter, deserter, sailor, bachelor), some of which were conformed from Latin to English in late Middle English.
The use of -or and -ee in legal language (e.g. lessor/lessee) to distinguish actors and recipients of action has given the -or ending a tinge of professionalism, and this makes it useful in doubling words
that have both a professional and non-professional sense (e.g. advisor/adviser, conductor/conducter, incubator/incubater, elevator/elevater).
comparative suffix, from Old English -ra (masc.), -re (fem., neuter), from Proto-Germanic *-izon, *-ozon (cf. Gothic -iza, Old Saxon -iro, Old Norse -ri, Old High German -iro, German -er), originally also
with umlaut change in stem, but this was mostly lost in Old English by historical times and has now vanished (except in better and elder).
For most comparatives of one or two syllables, use of -er seems to be fading as the oral element in our society relies on more before adjectives to express the comparative; thus prettier is more pretty,
cooler is more cool [Barnhart].
suffix used to make jocular or familiar formations from common or proper names (soccer being one), first attested 1860s, English schoolboy slang, "Introduced from Rugby School into Oxford University slang,
orig. at University College, in Michaelmas Term, 1875" [OED, with unusual precision].
1. a suffix used in forming nouns designating persons from the object of their occupation or labor ( hatter; tiler; tinner; moonshiner ), or from their place of origin or abode ( Icelander; southerner;
villager ), or designating either persons or things from some special characteristic or circumstance ( six-footer; three-master; teetotaler; fiver; tenner ).
2. a suffix serving as the regular English formative of agent nouns, being attached to verbs of any origin ( bearer; creeper; employer; harvester; teacher; theorizer ).
Compare -ier , -yer.
Middle English -er ( e ), a coalescence of Old English -ere agentive suffix (cognate with Old High German -āri, Gothic -areis < Germanic *-arjaz (> Slavic *-arĭ ) < Latin -ārius -ary) and Old
English -ware forming nouns of ethnic or residential orig. (as Rōmware Romans), cognate with Old High German -āri < Germanic *-warioz people
a noun suffix occurring in loanwords from French in the Middle English period, most often names of occupations ( archer; butcher; butler; carpenter; grocer; mariner; officer ), but also other nouns (
corner; danger; primer ). Some historical instances of this suffix, as in banker or gardener, where the base is a recognizable modern English word, are now indistinguishable from denominal formations
with -er 1 , as miller or potter.
Middle English < Anglo-French -er, equivalent to Old French -er, -ier < Latin -ārius, -ārium. Compare -ary, -eer, -ier
a termination of nouns denoting action or process: dinner; rejoinder; remainder; trover .
< French, orig. infinitive suffix -er, -re
a suffix regularly used in forming the comparative degree of adjectives: harder; smaller .
Middle English -er ( e ), -re, Old English -ra, -re; cognate with German -er
a suffix regularly used in forming the comparative degree of adverbs: faster .
Middle English -er ( e ), -re, Old English -or; cognate with Old High German -or, German -er
a formal element appearing in verbs having frequentative meaning: flicker; flutter; shiver; shudder .
Middle English; Old English -r-; cognate with German – ( e ) r-
a suffix that creates informal or jocular mutations of more neutral words, which are typically clipped to a single syllable if polysyllabic, before application of the suffix, and which sometimes undergo
other phonetic alterations: bed-sitter; footer; fresher; rugger . Most words formed thus have been limited to English public-school and university slang; few, if any, have become current in North America,
with the exception of soccer, which has also lost its earlier informal character.
probably modeled on nonagentive uses of -er1 ; said to have first become current in University College, Oxford, 1875–80