Refrigeration and air conditioning

The nineteenth entry is a formação de gelo, and the short word that ends it is one an English reader already owns several times over without noticing. Latin had gelu, frost, and the verb gelare, to freeze. Portuguese took both and wore them down to o gelo, the everyday word for what sits on the fins, on the pavement and in a glass. English went the other way. Its plain word for the thing, « ice », is Germanic, and the Latin root arrived later and through French, attached to everything except the cold itself. Gelata, the frozen thing, became Old French gelee and then « jelly », which sets on a plate and not on a roof; congelare gave « congeal »; the Italian gelatina gave « gelatine ». So a reader who has watched a stock congeal has had the root in hand all along and has never once thought of frost. Portuguese keeps the whole family in plain sight — gelar, congelar, o gelado, a geleia — so the technician writing a formação de gelo on a service sheet is using the word a child uses for an ice cream.