Rope for a cowboy in Dallas somewhere (5)
I believe the answer is:
lasso
'rope for a cowboy' is the definition.
(I've seen this before)
'in dallas somewhere' is the wordplay.
'in' says the answer is hidden in the clue.
'LASSO' is hidden in the letters of 'dallas somewhere'.
(Other definitions for lasso that I've seen before include "Catch (steers) with a rope" , "something to catch beast liable to run off" , "Nosed rope" , "which may be catching" , "Cowcatcher" .)