First want everything again to go in, covering the entire floor (4-2-4)
I believe the answer is:
wall-to-wall
'first want everything again to go in covering the entire floor' is the definition.
I can't tell whether this definition defines the answer.
'first want everything again to go in covering the entire' is the wordplay.
'first want' becomes 'w' (tst letter of 'want').
'everything' becomes 'all' (all things).
'again to go in' becomes 'tow' (I can't explain this - if you can you should believe this answer much more).
'covering' means one lot of letters go next to another (in a down clue, some letters go above others).
'the entire' becomes 'all' (I've seen this in other clues).
'w'+'all'+'tow'+'all'='WALL-TO-WALL'
Can you help me to learn more?
(Other definitions for wall-to-wall that I've seen before include "(Of carpet) fitted" , "Widespread" .)