Short illness brings abbreviation (11)
I believe the answer is:
curtailment
'abbreviation' is the definition.
(thesaurus)
'short illness' is the wordplay.
'short' becomes 'curt' (synonyms).
'illness' becomes 'ailment' (an ailment is an illness or health problem).
'curt'+'ailment'='CURTAILMENT'
'brings' acts as a link.
(Other definitions for curtailment that I've seen before include "Bringing to an end" , "premature end" , "Contraction" , "Abridgement, shortening" , "Terminal cut (anag) - downsizing" .)