An antagonistic muscle is a a muscle that counteracts the action of another muscle.
An agonistic muscle is a muscle that works in the same direction as another muscle.
Synergistic muscles are muscles that assist one another in action.
The muscles Glutues Medius are the antagonists to the hip abductors.
The muscles Abductor Longus and Abductor Magnus are the agonist.
The synergistic muscles of muscles Glutues Medius are the Psoas, Piriformis, TLF, Quadratus Lumborum and Rectus Femoris.
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I am terrible sorry. The word "adductor" was indeed misspelled and the answer was not clear.
Let me try again.
An agonist is a prime mover, while antagonist is a muscle whose action is the direct opposite of that of agonist.
The gluteus medius muscle is the prime mover responsible for hip abduction. It is an agonist.
The hip adductor muscles are the antagonists to the glutues medius.
The synergist muscles are the psoas, piriformis, TLF, quadratus lumborum and rectus femoris.
Agonists and antagonist are relative. If antagonists become prime mover, they are agonists and old agonists become antagonists. Thus, if the adductor muscles are prime movers, the muscles adductor longus and adductor magnus are the agonists. The muscle gracilis is synergist. The antagonists are muscles gluteus medius, TLF.