Disgustingly or distastefully sweet; causing surfeit through excess. Something cloying overwhelms with too much sweetness, whether literal or figurative, creating a nauseating effect.
From the verb 'cloy,' which originally meant 'to nail' or 'to fasten,' from Old French 'encloyer.' The meaning evolved to suggest being 'nailed down' or stuck by excessive sweetness, unable to escape the overwhelming sensation.
Think of eating too much cotton candy - at first it's delightful, but eventually the sweetness becomes overwhelming and makes you feel sick. Cloying things 'nail you down' with their excessive sweetness until you can't escape or enjoy them anymore.
Complete word intelligence in one call. Free tier — 50 lookups/day.