Tree in a mess, in consequence put down (7)
I believe the answer is:
entered
'put down' is the definition.
(I've seen this before)
'tree in a mess in consequence' is the wordplay.
'in a mess' indicates anagramming the letters.
'in' indicates putting letters inside.
'consequence' becomes 'end' (I've seen this in another clue).
'tree' anagrammed gives 'tere'.
'tere' inserted within 'end' is 'ENTERED'.
(Other definitions for entered that I've seen before include "moved in" , "Enrolled or went in" , "Ten deer (anag) - went in" , "Went in and registered as competitor" , "Logged; arrived" .)