Rugged? That's odd (6)
I believe the answer is:
uneven
I believe this is a double definition.
'rugged?' is the first definition.
(thesaurus)
'odd' is the second definition.
(thesaurus)
'that's' acts as a link.
(Other definitions for uneven that I've seen before include "Rough on the surface" , "Patchy" , "Odd - rough" , "Asymmetrical, not uniform" , "That's odd" .)