hoko

One root, and nothing to take off it. Hoko is a hook: the bent piece of metal you hang a coat on, the one on the end of a fishing line, the one on a crane. It does not divide, there is no prefix hiding at the front, and after several pages of words that reward taking apart it is worth having one that simply is what it is.

A rare Germanic root among the Romance. Esperanto's vocabulary leans heavily on Latin and the Romance languages, with Germanic showing up mostly in the small grammatical words (la, ĉu, nur, jaro) and in the hardware: ŝraŭbo a screw, bori to drill, haki to chop, and hoko. That is a pattern rather than a coincidence, and Zamenhof's principle was to take each root from wherever the international form already was.

The family, all transparent. Hoka is hooked, hoki is to hook something, hokforma is hook-shaped, and a hoketo is a small hook or the little hook you fasten a garment with. Fiŝhoko is the fishing hook specifically, which is what fiŝkapti needs, and ĉarhoko is a tow hook. A hook works because things pendas on it, and it is not a najlo, which goes straight in and holds by friction, nor a ŝnuro, which holds by being tied.