Dead centre of Gibraltar approached from the side (7)
I believe the answer is:
lateral
'approached from the side' is the definition.
(as in a lateral move)
'dead centre of gibraltar' is the wordplay.
'dead' becomes 'late' (similar in meaning).
'centre of' means to look at the middle letters.
The middle letters of 'gibraltar' are 'ral'.
'late'+'ral'='LATERAL'
(Other definitions for lateral that I've seen before include "Tall ear (anag.)" , "Sideways, like creative thinking" , "Edgeways" , "Side branch" , "This kind of sideways thinking does not use conventional logic" .)