I. noun
1.
Synonyms: substitute 1, alternate, backup, fill-in, locum tenens, pinch hitter, replacement, stand-in, sub, succedaneum
2.
Synonyms: resource 3, dernier ressort, expediency, expedient, makeshift, recourse, refuge, resort, stopgap, substitute
II. adjective
Synonyms: substitute 1, alternate, alternative, backup