noun

A thing added to something else as a supplementary rather than an essential part.

computer technology is an adjunct to learning

supplement,addition,accompaniment,complement,companion,extra,add-on,additive,accessory,appurtenance

adjective

Connected or added to something, typically in an auxiliary way.

other alternative or adjunct therapies include immunotherapy

additional,supplementary,supplemental,extra,reserve,backup,emergency,fallback,spare,substitute,other