Football club stadium skirting small lake (7)
I believe the answer is:
arsenal
'football club' is the definition.
(I've seen this before)
'stadium skirting small lake' is the wordplay.
'stadium' becomes 'arena' ('arena' can be a synonym of 'stadium').
'skirting' is an insertion indicator.
'small' becomes 's' (abbreviation - e.g. clothes size).
'lake' becomes 'l'.
'arena' going around 's' is 'arsena'.
'arsena'+'l'='ARSENAL'
(Other definitions for arsenal that I've seen before include "Weapons/ammo store" , "English football club and military depot" , "Store of weaponry" , "Highbury football team" , "2014 and 2015 FA Cup winners" .)