Relaxed in a seat, sprawling, with little energy (2,4)
I believe the answer is:
at ease
'relaxed' is the definition.
(similar in meaning)
'a seat sprawling with little energy' is the wordplay.
'sprawling with' indicates an anagram.
'little' says to take the initial letters.
The first letter of 'energy' is 'e'.
'seat' mixed up with 'e' gives 'tease'.
'a'+'tease'='AT EASE'
'in' is the link.
(Other definitions for at ease that I've seen before include "Relaxed, not tense - that's an order" , "Army command to relax, stand with feet apart" , "In a relaxed attitude" , "'Relaxed (2,4)'" , "Free from anxiety" .)