molasses

Molasses comes from Portuguese melaços or Spanish melazos, tracing back to Late Latin mellacium, a 'honey-sweet thing,' built from mel ('honey') plus the suffix -āceus. Some English forms may instead reflect Spanish melaza or French mélasse, possibly from an unattested Late Latin mellacea.

The word entered English through Iberian trade languages, carrying its Latin root's association with honeyed sweetness even as it came to describe a specific sugar-refining byproduct rather than honey itself.

It shares its root, Latin mel ('honey'), with the -aceus suffix pattern seen in other 'honey-sweet' derived words.