Like Superman's chin, famously (5)
I believe the answer is:
cleft
(Other definitions for cleft that I've seen before include "Chin split" , "Space" , "Split, divided" , "division" , "Opening, fissure" .)
I believe the answer is:
cleft
(Other definitions for cleft that I've seen before include "Chin split" , "Space" , "Split, divided" , "division" , "Opening, fissure" .)