latomus.

Borrowed from Ancient Greek λᾱτόμος (lātómos, “stonecutter”), from λᾶᾰς (lâăs, “stone”) + τόμος (tómos, “cutting”), from τέμνω (témnō, “to cut”). The collateral form lautumus reflects the variant λᾱοτόμος (lāotómos) and shows adaptation to Latin phonotactics (āo→au) as well as vowel weakening in middle syllables (o→u), which suggests that it's the older form and lātomus is a younger, more literal borrowing.