Outline argument against travel (7)
I believe the answer is:
contour
'outline' is the definition.
(contouring is a kind of outlining)
'argument against travel' is the wordplay.
'argument' becomes 'con' (con is a kind of argument).
'against' says to put letters next to each other.
'travel' becomes 'tour' (tour is a kind of travel).
'con'+'tour'='CONTOUR'
(Other definitions for contour that I've seen before include "Silhouette" , "Outline, profile" , "Outline (of land)" , "Outline, shape" , "Map line of equal altitude" .)