dilator

noun

di·la·tor | \ (ˈ)dī-ˈlāt-ər, də-

Medical Definition of dilator

: one that dilates: as

a : an instrument for expanding a tube, duct, or cavity a urethral dilator

— called also divulsor

b : a muscle that dilates a part

c : a drug (as a vasodilator) causing dilation