Dress up as necessary to get to Gateshead (3)
I believe the answer is:
tog
'dress up' is the definition.
(I've seen this in another clue)
'get to gateshead' is the wordplay.
'get' says to put letters next to each other.
'gateshead' becomes 'g' (head letter of 'gates').
'to' put next to 'g' is 'TOG'.
'as necessary to' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for tog that I've seen before include "Quilt rating" , "Duvet rating" , "Unit of thermal resistance, used for duvets" , "Get up" , "Measure of warmth" .)