Fruit squash almost covers it (6)
I believe the answer is:
'fruit' is the definition.
(I know that citrus is a type of fruit)
'squash almost covers it' is the wordplay.
'squash almost' becomes 'crus' (I can't justify this - if you can you should believe this answer much more).
'covers' is an insertion indicator.
'crus' placed around 'it' is 'CITRUS'.
Can you help me to learn more?
(Other definitions for citrus that I've seen before include "it bears fruit" , "Fruits such as oranges or lemons" , "Describing lemons, for example" , "Fruit tree genus" , "Rustic (anag) - type of fruit" .)