A depression engulfing knave almost touching (8)
I believe the answer is:
adjacent
'touching' is the definition.
(thesaurus)
'a depression engulfing knave almost' is the wordplay.
'depression' becomes 'dent' ('dent' can be a synonym of 'depression'**).
'engulfing' is an insertion indicator.
'knave' becomes 'jack' (I've seen this before).
'almost' means to remove the last letter (most of the word but not all of it).
'jack' with its final letter removed is 'jac'.
'dent' going around 'jac' is 'djacent'.
'a'+'djacent'='ADJACENT'
(Other definitions for adjacent that I've seen before include "Contiguous" , "Near - juxtaposed" , "Next (to something)" , "Close by" , "Next-door" .)