-er

UK [ə(r)] / US [ər] suffix

1) used with many verbs to make nouns meaning someone or something that performs an action

a writer

a cooker

2) used with some nouns to make other nouns meaning someone who is involved with something, especially as a job

a philosopher

a biographer

3) used with the names of some cities to mean someone who comes from a place

a Londoner

a New Yorker

4) used with short adjectives and adverbs to make the comparative

bigger

easier

faster