Meaning of the Sanskrit Word: kartaram

  kartaram—the doer    SB 1.17.13, SB 6.17.19
  kartaram—the father    Bg 4.13
  kartaram—the performer    Bg 14.19
  kartaram—of the worker    Bg 18.16
  kartaram—maker    SB 4.25.33

Can't find any compound Sanskrit words containing kartaram.