Suit
Middle English: from Anglo-Norman French siwte, from a feminine past participle of a Romance verb based on Latin sequi ‘follow’. Early senses included ‘attendance at a court’ and ‘legal process’; suit (sense 1 of the noun and sense 2 of the noun) derive from an earlier meaning ‘set of things to be used together’. The verb sense ‘make appropriate’ dates from the late 16th century.
wiktionary
From Middle English sute, borrowed from Anglo-Norman suite and Old French sieute, siute (modern suite), originally a participle adjective from Vulgar Latin *sequita (for secūta), from Latin sequi(“to follow”), because the component garments "follow each other", i.e. are worn together. See also the doublet suite. Cognate with Italian seguire and Spanish seguir. Related to sue and segue.
etymonline
suit (n.)
c. 1300, sute, also suete, suite, seute, "a band of followers; a retinue, company;" also "set of matching garments" worn by such persons, "matching livery or uniform;" hence " kind, sort; the same kind, a match;" also "pursuit, chase," and in law, "obligation (of a tenant) to attend court; attendance at court," from Anglo-French suit, siwete, from Old French suite, sieute "pursuit, act of following, hunt; retinue; assembly" (12c., Modern French suite), from Vulgar Latin *sequita, fem. of *sequitus, from Latin secutus, past participle of sequi "to attend, follow" (from PIE root *sekw- (1) "to follow").
Legal sense of "lawsuit; legal action" is from mid-14c. Meaning "the wooing of a woman" is from late 15c. Meaning "set of clothes to be worn together" is attested from late 14c., also "matching material or fabric," from notion of the livery or uniform of court attendants. As a derisive term for "businessman," it dates from 1979. Meaning "matched set of objects, number of objects of the same kind or pattern used together" is from late 14c., as is that of "row, series, sequence." Meaning "set of playing cards bearing the same symbol" is attested from 1520s, also ultimately from the notion of livery. To follow suit (1670s) is from card-playing: "play a card of the same suit first played," hence, figuratively, "continue the conduct of a predecessor."
suit (v.)
"be agreeable or convenient, fall in with the views of," 1570s, from suit (n.), perhaps from the notion of "join a retinue clad in like clothes." Earlier "seek out" (mid-15c.); "be becoming" (mid-14c.). Meaning "make agreeable or convenient" is from 1590s. Meaning "provide with clothes" is from 1570s; that of "dress oneself" is from 1590s; with up (adv.) from 1945. Expression suit yourself attested by 1851. Related: Suited; suiting.
