Absence somehow contented Anna (3-10)
I believe the answer is:
non-attendance
'absence' is the definition.
(I've seen this before)
'somehow contented anna' is the wordplay.
'somehow' indicates an anagram.
'contented'+'anna'='contentedanna'
'contentedanna' is an anagram of 'NON-ATTENDANCE'.
(Other definitions for non-attendance that I've seen before include "Failure to appear" , "Absence" .)