Definition of -ster in US English:

-ster

suffix

  • 1Denoting a person engaged in or associated with a particular activity or thing.

    ‘songster’
    ‘gangster’
  • 2Denoting a person having a particular quality.

    ‘youngster’

Origin

Old English -estre, -istre, etc., of Germanic origin.

Pronunciation

-ster

/stə/