Mesa's kin (5)
I believe the answer is:
butte
'mesa's kin' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for butte that I've seen before include "Isolated steep-sided flat-topped hill" , "Hill with steeply sloping sides and flat top - town in Montana" , "Steep sided hill" , "American hill" .)