suit

The root suit is the everyday, French-dressed face of one of Latin's most important verbs: sequī, 'to follow' (past participle secūta). The same verb gives English the bookish family sequence, consequence, and pursue through the spelling sequ-/secut-. But suit took a different road. Vulgar Latin turned secūta into sequita, which Old French wore down to suite (also spelled sieute), meaning literally 'a following' — and, more concretely, a set of things that follow one another, that belong together.

That single image — things that go together — is the key that unlocks the whole family.

Start with clothing. A suit is a jacket and trousers (or skirt) cut from the same cloth so they follow, or match, each other — a set that belongs together. The same logic runs through a deck of cards: the four suits (hearts, spades, clubs, diamonds) are the four matching sets. When you 'follow suit' in a card game you literally play a card of the same set, and the phrase has become an everyday idiom for 'do the same as someone else.'

Now let the idea of matching become abstract. If something matches you — fits your needs, goes well with you — it suits you: 'that color suits you,' 'does Tuesday suit you?' From this verb comes the adjective suitable ('fit to follow along, matching the purpose') and its opposite unsuitable. A suitcase is, very plainly, the case you pack your suit (your set of clothes) in — now any travel bag.

A third branch went into the courtroom. In Old French, to follow a matter through the legal system was to pursue it; a suit became a legal action, and lawsuit spells that out — a 'following' of the law against someone.

Finally, the older French spelling suite survived intact for 'a connected set': a suite of hotel rooms that open into one another, a suite of furniture, and in music a suite — several movements that follow one another as a group. The same word can also mean a great person's suite of attendants: the people who follow them.

So every member traces back to one picture — a following, a set that belongs together — and then specializes: matching clothes and cards (suit), matching your needs (suit, suitable), following a case through court (lawsuit), and a connected group of rooms, pieces, or people (suite).