Meaning of the Sanskrit Word: mahiyasam

  mahéyasäm—of the great personalities, devotees    Madhya 22.53, Madhya 25.85
  mahéyasäm—of the greatest    SB 1.19.30
  mahéyasäm—of the most powerful    SB 4.5.5
  mahéyasäm—among other great personalities    SB 6.15.10
  mahéyasäm—of the great souls (the mahätmäs, or devotees)    SB 7.5.32

Can't find any compound Sanskrit words containing mahiyasam.