'sand-preferring' originates from Modern English as a compound of the noun 'sand' and the present participle 'preferring' (from the verb 'prefer').

'preferring' ultimately comes from Latin via Old French: Latin 'praeferre' ('prae-' + 'ferre') > Old French 'preferer' > Middle English 'preferen/prehferen' > Modern English 'prefer', with the present participle form developing regularly; 'sand' comes from Old English 'sand'. The compound 'sand-preferring' is a transparent modern formation.

Initially both elements ('sand' and 'prefer') retained their original senses; combined, the compound straightforwardly came to mean 'showing a preference for sand' and has had no major semantic shift.