Steamy sections of highway crossing America to the west (7)
I believe the answer is:
sensual
'steamy' is the definition.
(I've seen this in another clue)
'sections of highway crossing america to the west' is the wordplay.
'sections of highway' becomes 'lanes' (I've seen this in another clue).
'crossing' indicates putting letters inside.
'america' becomes 'US' (United States).
'to the west' says the letters should be written in reverse (letters written right to left or 'east to west').
'lanes' placed around 'us' is 'lausnes'.
'lausnes' reversed gives 'SENSUAL'.
(Other definitions for sensual that I've seen before include "Carnal" , "creating gratification" , "Relating to touch, etc" , "Unseals (anag.)" , "Sultry" .)