sclerotherapy Syllabification: (scle·ro·ther·a·py)Pronunciation: /ˌskli(ə)rəˈTHerəpē/Definition of sclerotherapy noun Medicine the treatment of varicose blood vessels by the injection of an irritant that causes inflammation, coagulation of blood, and narrowing of the blood vessel wall. sclerotherapy in other Oxford dictionaries Definition of sclerotherapy in the British & World English dictionary