Meaning of the Sanskrit Word: kartaram

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

Can't find any compound Sanskrit words containing kartaram.