is a specific kind of: fit, match.

is a broader term that covers: complement | compensate, correct, counterbalance, even off, even out, even up, make up | cancel, offset, set off | countervail, offset | trim.

verb group: balance, poise | balance.

is the opposite of: unbalance.

derivation: equilibrium, labyrinthine sense, sense of balance, sense of equilibrium, vestibular sense | chemical equilibrium, equilibrium | balance, counterbalance, equilibrium, equipoise | equilibrium | balance.