Outline cruise’s launch when travelling (7)
I believe the answer is:
contour
'outline' is the definition.
(contouring is a kind of outlining)
'cruise's launch when travelling' is the wordplay.
'cruise's launch' becomes 'c' (I am not sure about this - if you are sure you should believe this answer much more).
'when' becomes 'on' (I've seen this in other clues).
'travelling' becomes 'tour' (tour is a kind of travelling).
'c'+'on'+'tour'='CONTOUR'
Can you help me to learn more?
(Other definitions for contour that I've seen before include "Outline, profile" , "Defining line" , "Map line of equal altitude" , "Feature on map" , "Line on map indicating height" .)