maniko

The false seam, and why it is the good kind. The word looks like mano plus an ending, and a learner who has met -ik- in muziko and tekniko may try to cut it there. Do not: Esperanto has no productive -ik- suffix meaning pertaining to, and even if it did, a sleeve is not especially hand-ish. It goes on the arm.

And yet the hand is genuinely in there. Latin manica is built on manus, the hand, because a Roman sleeve was the part of the tunic that reached down over the wrist and covered it. So the seam is false in Esperanto, where maniko is one indivisible root, and real in Latin, where it was cut exactly where you thought. This is the same class as inspiri, which looks like in- plus spiri and is not, except that in Latin it was. English gets manacle from the same manus, which is a sleeve for the hand of a rather different kind.

Wearing it. Senmanika is sleeveless, mallonga maniko is a short sleeve, and manumo is the cuff at the end of it. Esperanto also keeps the English idiom about having something up your sleeve: havi ion en la maniko. And a maniko in machinery is a sleeve in the engineering sense too, a tube slid over something else, which is the same picture.