Synonyms of backup

1 Syllable
dh, sub, aid
2 Syllables
helpers, henchman, fill-in, proxies, sparer, standby, substract, locum, sparest, helper, extra, stand-in, brancher, henchmen, proxy
3 Syllables
deputy, lieutenant, assistant, changeling, pinch-hitter, supplanter, adjuvant, mediary, assignee, deputies, vicarial, reliever, re-serve, relievers
4 Syllables
auxiliaries, alternate, surrogate, temporaries, substituted, supportive, secondaries, cooperator, substitute, succedaneum, cooperators, secondary, understudy, auxiliary, substituting, tributory, representant, subsidiary
5 Syllables
substitutive, second-in-command
6 Syllables
paraprofessional, paraprofessionals