matura

Two senses, one word. Matura is ripe when it is about fruit or grain, and mature when it is about people, judgement or a plan. Esperanto does not split them the way English half does, so matura pomo and matura homo sit comfortably in the same vocabulary.

A false seam with a twist. The parse mat- plus -ur- is impossible: there is no suffix -ur- in Esperanto and no root mat-. So far, ordinary. The twist is mateno, morning, which looks like a cousin and is not one inside Esperanto - maten- and matur- are two separate borrowed roots and neither is built from the other. But go back far enough in Latin and the resemblance stops being accidental: maturus and matutinus do share an ancestor, the idea of the right early hour. The seam is false in the language you are learning and half-true in the language it came from, which is exactly the kind of thing that makes learners distrust their own instincts. Trust the Esperanto rule; the Latin is a story, not a build.

The derivations are regular and useful: maturiĝi is to ripen (something the fruit does to itself), maturigi is to ripen something else, matureco is maturity, and nematura is unripe or immature. Mature is the adverb - agi mature, to act like an adult.