Tree chap’s seen in front of spinney (8)
I believe the answer is:
mangrove
'tree' is the definition.
(mangrove is a kind of tree)
'chap's seen in front of spinney' is the wordplay.
'chap' becomes 'man' (I've seen this before).
'seen in front of' says to put letters next to each other.
'spinney' becomes 'grove'.
'man'+'grove'='MANGROVE'
(Other definitions for mangrove that I've seen before include "Evergreen" , "whose roots may be waterlogged" , "that grows in swamps" , "Tree growing on tropical coasts and in muddy swamps" , "Strange tree of tropical swamps is a veg, Norma" .)