matur

The root matur comes from the Latin adjective mātūrus, meaning "ripe, mature, timely" — and from the verb mātūrāre, "to ripen, to bring to ripeness." The original picture is agricultural: fruit that has hung on the branch long enough to be ready, grain ripe for harvest. Mātūrus carried a second flavor too — "timely," happening at the right moment — because a ripe fruit is one that has come due at its proper time. Hold on to those two ideas, "fully ripened" and "at the right time," because the whole family pivots on them.

The base word mature keeps both senses. A mature apple is ripe; a mature person is fully grown and fully developed; a bond or loan that has matured has reached the time it falls due. That last sense — finance — is pure "timely": the debt has arrived at its proper moment for payment.

From there the prefixes do their usual work, mostly playing with time:

- pre- (before) + matur → premature: ripened before its proper time. A premature baby arrives before full term; a premature conclusion is reached before the evidence is in. The word always carries a faint sense of "too early, jumped the gun."
- in-/im- (not) + matur → immature: not ripe, not fully grown — a green fruit, or, of a person, childish.
- -ity turns the adjective into a state: maturity is the condition of being ripe/grown, and again in finance, the date a bond comes due (maturity date).

A warning worth flagging: matur looks a lot like mat- in words such as automatic and automaton, but they are unrelated. Those come from Greek automatos ("acting of itself"); this matur is Latin and is about ripeness, not self-action. We deliberately split matur out as its own root so the Latin "ripe/timely" family isn't tangled with the Greek "self-moving" one.

The pattern across the family is simple: matur is always "ripe / fully developed / at the right time," and the prefix tells you the timing — pre- too early, im- not yet. Read every word as a question about ripeness and timing and they all fall into place.