Plant belonging to you and me (5)
I believe the answer is:
'plant' is the definition.
(thyme is a kind of plant)
'belonging to you and me' is the wordplay.
'belonging to you' becomes 'thy' (belonging to thee).
'and' is a charade indicator (letters next to each other).
(Other definitions for thyme that I've seen before include "Seasoning plant" , "Aromatic plant" , "Herb with fragrant leaves - parsley, sage, rosemary and . . . . ." , "Kind of mint" , "Meadow herb" .)