From Latin 'bellus' (pretty) — the informal, warm Latin word that defeated formal 'pulchritūdō' in every Romance language.
A combination of qualities, such as shape, colour, or form, that pleases the aesthetic senses; a beautiful person or thing.
From Anglo-Norman 'beauté,' from Old French 'bealté' or 'biauté' (modern French 'beauté'), from Vulgar Latin *bellitātem, from Latin 'bellus' (pretty, handsome, fine), possibly a diminutive or colloquial form of 'bonus' (good) via an intermediate *dvenelos → *benelos → *bellos. The Classical Latin word for beauty was 'pulchritūdō,' but the colloquial 'bellus' won out in the Romance languages. The word entered English with the Norman aristocracy's vocabulary
Classical Latin's formal word for beauty was 'pulchritūdō' — which English borrowed as 'pulchritude,' a word so ugly-sounding that it seems to contradict its own meaning. Spoken Latin preferred the informal, warmer 'bellus' (pretty), which won the evolutionary battle: every Romance language uses a descendant of 'bellus' for beauty, while 'pulchritūdō' survives only as a literary curiosity.