accessorial

available to supply something extra when needed an accessorial service, such as packing, will add substantially to the moving company's basic fee Synonyms auxiliary, accessory, appurtenant, peripheral, supplemental, supplementaryRelated Words backup, makeshift, substitute; added, additional, another, further; complementary, contributory; adjuvant, assistant, assisting, helping, supportive, tributary; secondary, subordinate, subservient, subsidiary; dispensable, excess, nonessential, superfluous, surplus, unessentialNear Antonyms basic, fundamental, primary, prime; all-important, essential, imperative, indispensable, integral, necessary, needed, needful, required, requisite, vitalAntonyms chief, main, principal