UNDERLEASE Meaning of UNDERLEASE in English I. ˈ ̷ ̷ ̷ ̷ˌ ̷ ̷ nounEtymology: under (III) + lease : sublease II. | ̷ ̷ ̷ ̷| ̷ ̷ verb : sublet Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012