journal

Journal comes from Middle English journal, from Anglo-Norman jurnal ("daily"), from Old French jornel ("day"), from Latin diurnālis, tied to diurnus ("of the day"). It's a doublet of diurnal — both descend from the same Latin root, one through Old French, one straight from Latin.

The word started as an adjective meaning simply "daily," describing something that happens or recurs each day. Over time it settled into English as a noun for the daily record itself — the thing you keep, not just the frequency it keeps.

It's a doublet of diurnal, meaning both words trace back to the same Latin ancestor, diurnus, but arrived in English by different routes.