detumescence
noun
de·tu·mes·cence ˌdē-t(y)ü-ˈme-sᵊn(t)s 
: subsidence or diminution of swelling or erection
detumescent
ˌdē-t(y)ü-ˈme-sᵊnt
adjective 
Word History
Etymology
Latin detumescere to become less swollen, from de- + tumescere to swell — more at tumescent
First Known Use
1678, in the meaning defined above
Medical Definition
detumescence
noun
de·tu·mes·cence ˌdē-t(y)ü-ˈmes-ᵊn(t)s
: subsidence or diminution of swelling or erection