Definition of -er suffix from the Oxford Advanced Learner's Dictionary

  1. 1(in nouns) a person or thing that lover computer compare -ee, -or
  2. 2(in nouns) a person or thing that has the thing or quality mentioned three-wheeler foreigner
  3. 3(in nouns) a person concerned with astronomer philosopher
  4. 4(in nouns) a person belonging to New Yorker
  5. 5(makes comparative adjectives and adverbs) wider bigger happier sooner compare -est More Like This Suffixes -able, -age, -al, -ance, -ant, -arian, -ary, -dom, -ee, -er, -ese, -esque, -ess, -fold, -ful, -hood, -ify, -ion, -ish, -ism, -ist, -ista, -ite, -itis, -ize, -less, -let, -ling, -ly, -ment, -most, -ness, -oid, -or, -ous, -shipSee worksheet.
See the Oxford Advanced American Dictionary entry: -er