before vowels mult-, word-forming element meaning "many, many times, much," from combining form of Latin multus "much, many," from PIE *ml-to-, from root *mel- (2) "strong, great, numerous." It was much-used in forming Latin compounds in classical times and after (such as multianimis "having much courage," multibibus "much-drinking," multicomus "having much hair," multiloquus "talkative"). Many English words that use it (multinational, etc.) are 20c. coinages.
c. 1200, "act of employing," from Anglo-French and Old French us "custom, practice, usage," from Latin usus "use, custom, practice, employment, skill, habit," from past participle stem of uti "make use of, profit by, take advantage of" (see use (v.)).
<a href="https://www.etymonline.com/word/multi-use">Etymology of multi-use by etymonline</a>
Harper, D. (n.d.). Etymology of multi-use. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/multi-use