Informal, chiefly childish usage referring to a person or thing that smells unpleasant.
Definitionen
Informal: a person or thing that has an unpleasant smell. The other kids called him a smelly because of his dirty clothes.
British informal, usually plural: scented toiletries or personal care products, especially those with a noticeable fragrance. She filled the gift bag with bath smellies and candles.