Friend with Very light secures British patent (8)
I believe the answer is:
palpable
'patent' is the definition.
(thesaurus)
'friend with very light secures british' is the wordplay.
'friend' becomes 'pal' (pal is a kind of friend).
'with' says to put letters next to each other.
'very light' becomes 'pale' (with a pale colour).
'secures' indicates putting letters inside.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'pale' going around 'b' is 'pable'.
'pal'+'pable'='PALPABLE'
(Other definitions for palpable that I've seen before include "Able to be touched/felt" , "Apparent" , "Easily perceived by the senses" , "Evident - tangible" , "Able to be touched or felt - like a hit" .)