-ator

a combination of -ate1 and -or2 that forms nouns corresponding to verbs ending in -ate1,denoting a human agent (agitator; mediator; adjudicator) or nonhuman entity, especially a machine (incubator; regulator; vibrator) performing the function named by the verb.
Compare -tor, -or2.

Origin of -ator

< Latin -ātor, orig. not a suffix, but the termination of nouns formed with -tor -tor from verbs whose stems ended in -ā-; in English, Latin loanwords ending in -ātor have been reanalyzed as derivatives of the past participles in -tus (see -ate1) and a suffix -or (see -or2), and many new English nouns derived from English verbs based on Latin past participles (e.g., vibrator from vibrate)

Words nearby -ator

-ate, -athon, -atic, -ation, -ative, -ator, -atory, -bacter, -bashing, -biont, -biosis

British Dictionary definitions for -ator

-ator

suffix forming nouns

a person or thing that performs a certain action agitator; escalator; radiator

Word Origin for -ator

from Latin -ātor; see -ate 1 -or 1