Oddly unseen, Brummie punches head of Parisian six-footer (7)
I believe the answer is:
termite
'six-footer' is the definition.
(I've seen this before)
'oddly unseen brummie punches head of parisian' is the wordplay.
'oddly unseen' indicates alternate letters (letters in odd-numbered positions removed).
'punches' indicates putting letters inside (punch can mean to create a hole in).
'head of parisian' becomes 'tete' ('head' in French).
The alternating letters of 'brummie' are 'rmi'.
'rmi' inserted inside 'tete' is 'TERMITE'.
(Other definitions for termite that I've seen before include "Woodworm of warmer regions" , "Ant-like insect which destroys timber" , "Mound-dweller" , "Social type" , "Wood-ant" .)