kaĉo

Kaĉo is boiled grain or vegetable cooked soft: porridge, mash, a purée. Kaĉo el avenaj grajnoj is breakfast; kaĉo da terpomoj is mashed potato. It is also, and just as commonly, a mess - a muddle where the parts have stopped being distinguishable. Ĉu estas kaĉo en via kapo? is a real Esperanto sentence and it means what you think it means. Wet snow underfoot is kaĉo; so is a badly run committee.

The proverb collection has the classic: kiu kaĉon kuiris, tiu ĝin manĝu - whoever cooked the porridge, let him eat it. English says "you made your bed, now lie in it". The Esperanto is older, ruder and better.

One near-pair to dismiss before it worries you. Written in the x-system kaĉo is kacxo, which sits close to kato, a cat, on the page and nowhere near it in meaning or sound. There is no shared root and no affix seam here: kaĉ- is a single borrowed root, and the resemblance is three letters of coincidence. Say them aloud - KA-cho against KA-to - and the worry goes.