Ketman wrote:So does "lapis" also mean "insensate" or "lacking in empathy"?
Craig_Thomas wrote:Lapis cannot itself be used as an adjective, unless you think of a noun's genitive as adjectival, which in a sense it is.
One common way of making nouns into adjectives, when talking about the material of which something is made, is with the addition of -eus -ea -eum. So, lāneus means 'woolen' (from lāna, 'wool'), ferreus means 'of iron' (from ferrum, 'iron'), ligneus means 'wooden' (from lignum, 'wood'), and similarly aureus, argenteus, and, indeed, lapideus. Another way is to add -ōsus -ōsa -ōsum to the noun's stem, equivalent to '-ful' in English. So, formōsus means 'beautiful' (from forma, 'beauty, form'), cūriōsus means 'careful' (from cūra, 'care') and so on. Lapidōsus means 'stony' or 'full of stone'.
Both lapideus and lapidōsus could, I think, be understood as meaning 'hard-hearted' or 'unfeeling', though the usual word for this in Latin is dūrus.
Those are the two ways of adjectifying a noun that are relevant to your question, but there are other ways. For instance, the addition of -fer -fera -ferum (or -ger -gera -gerum) makes an adjective meaning '____-carrying'. Lucifer means 'light-bearing' or 'radiant one', mare navigerum means 'ship-carrying' or 'navigable sea', Aeneas penātifer is 'Penates-carrying Aeneas', and, to coin a word, servi lapidiferi would be 'stone-carrying slaves'.