Words grouped so they carry meaning together that none carries alone. The unit between word and sentence.
Greek φράσις (phrasis, a speaking, manner of expression), from φράζειν (phrazein, to point out, declare); words grouped so the pointing they do together is more than any one of them carries alone.
Words grouped so that, together, they carry a meaning none of them carries alone — the unit that sits between a single word and a full sentence.