Against having trip — something seen on map? (7)
I believe the answer is:
contour
'something seen on map?' is the definition.
'against having trip' is the wordplay.
'against' becomes 'con' (I've seen this before).
'having' means one lot of letters go next to another.
'trip' becomes 'tour' (I've seen this before).
'con'+'tour'='CONTOUR'
(Other definitions for contour that I've seen before include "Feature on map" , "Outline, profile" , "Silhouette" , "Map line of equal altitude" , "Defining line" .)