Absorb meal as it is mashed up (10)
I believe the answer is:
assimilate
'absorb' is the definition.
('assimilate' can be a synonym of 'absorb')
'meal as it is mashed up' is the wordplay.
'mashed up' indicates an anagram (I've seen this in other clues).
'meal'+'as'+'it'+'is'='mealasitis'
'mealasitis' is an anagram of 'ASSIMILATE'.
(Other definitions for assimilate that I've seen before include "thoroughly understood" , "Become part of the prevailing culture" , "pick up" , "Take in and understand" , "Absorb and digest (food)" .)