Meaning of the Sanskrit Word: rajasu

  rājasu—the governing personalities    SB 1.3.25
  rājasu—unto the kings    SB 1.8.37
  rājasu—upon the kings of that type    SB 2.7.20
  rājasu—among the kings headed by Jarāsandha    Adi 6.73

Can't find any compound Sanskrit words containing rajasu.