Meaning of the Sanskrit Word: vayasyaih

  vayasyaiḥ—with Their playmates    SB 10.8.27, SB 10.11.41
  vayasyaiḥ—by his friends of the same age    SB 7.5.54
  vayasyaiḥ—with Their friends of the same age    Adi 4.155

Can't find any compound Sanskrit words containing vayasyaih.