tumescent
adjective /tjuːˈmesnt/
  /tuːˈmesnt/
(formal)- (especially of parts of the body尤指身体部位 (尤指由于性冲动而)胀大的 词源mid 19th cent.: from Latin tumescent- ‘beginning to swell’, from the verb tumescere, from tumere ‘to swell’.