kilo

The word that kept failing the ceiling. Back in chapter 14, the grammar article on quantity and da needed a plain everyday example of weight. Kilogramo had no page and sat at rank 1830, above that chapter's vocabulary ceiling. The obvious short alternative was kilo, and kilo sits here, at rank 2396, which failed the ceiling considerably harder. The article ended up teaching peco da pano instead, a piece of bread, and kilo has been the ghost at the feast for eleven chapters. It arrives now. You may consider the debt settled and the ceiling honoured.

The measure. Kilo- is the SI prefix for a thousand, from Greek khilioi, and Esperanto uses the international prefixes exactly as the metric system defines them: kilogramo, kilometro, kilovato, kilobajto, and downwards through centimetro and miligramo. That single fact hands you several hundred words you never have to learn. Standing alone, kilo is the everyday clipping of kilogramo, exactly as in English, French and Spanish: du kiloj da terpomoj is what somebody actually says at a market stall.

And now the complication, which is a good one. Look kilo up in the Reta Vortaro and the entry you land on is a ship's keel: malsupra ĉeftrabego, iranta de la antaŭa ĝis la posta parto de ŝipo, the great lower beam running from the front of a vessel to the back. That is a wholly separate root, the Germanic word behind English keel and German Kiel, and it got to the dictionary first. Which left the weight with a problem, because kilo- is a prefix and a prefix cannot simply take -o when the resulting word is already occupied.

The Reta Vortaro's answer is kiloo, with two o's: milo da, el subkomprenata mezuro (kutime gramoj) - a thousand of some understood unit, usually grams. It is a tidy solution and almost nobody writes it. In practice Esperantists write plain kilo for the weight and let context sort it out, on the sensible grounds that a sentence about apples is not about boats. This page teaches both senses because both are real, and it is worth knowing that the strict form exists if you ever meet it.

Two notes on form. The abbreviation is kg, with no full stop and no -j in the plural. And the noun after kilo takes da, not de, because the kilo is measuring it out: kilo da pano, but la kilo de la ŝipo, where nothing is being measured at all.