A plane going up or coming down (4)
I believe the answer is:
ramp
'coming down' is the definition.
The answer and definition can be both to do with contact as well as being verbs in their base form.
Maybe they are linked in a way I don't understand?
'a plane going up' is the wordplay.
I cannot really understand how this works, but
'a' could be 'amp' (A is the symbol for the amp or ampere) and 'amp' is found in the answer.
A single letter 'r' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'or' is the link.
Can you help me to learn more?
(Other definitions for ramp that I've seen before include "Incline" , "One with an inclination" , "Sloping surface connecting two levels" , "aircraft steps?" , "Short slope" .)