-  Cloy originally meant ‘fasten with a nail’. It is a reduced form of the long obsolete acloy, which came from Anglo-Norman acloyer. This was a variant of Old French encloyer, a descendant of the Vulgar Latin compound verb inclāvāre, based on Latin clāvus ‘nail’ (source of Latin claudere ‘shut’, from which English gets close). => CLOSE
The Hutchinson dictionary of word origins. 2013.