I earn it from doing very little (7)
I believe the answer is:
inertia
'little' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'i earn it from doing' is the wordplay.
'i earn it' anagrams to 'INERTIA'.
Though, I'm not sure how the anagram is indicated.
'very' acts as a link.
Can you help me to learn more?
(Other definitions for inertia that I've seen before include "Change-resisting tendency" , "Disinclination to move" , "I retain (anag) - the tendency to retain same speed and direction" , "Apathy" , "'Sluggishness, indolence (7)'" .)