Jumper on male that is extremely short and extremely baggy (8)
I believe the answer is:
roomiest
'extremely baggy' is the definition.
(roomy can mean baggy or loose)
'jumper on male that is extremely short' is the wordplay.
'jumper' becomes 'roo' (I've seen this before).
'on' says to put letters next to each other.
'male' becomes 'm' (common abbreviation).
'that is' becomes 'i.e.' (synonyms).
'extremely' says to hollow out the word (remove centre letters).
'short' with its centre removed is 'st'.
'roo'+'m'+'ie'+'st'='ROOMIEST'
'and' acts as a link.
(Other definitions for roomiest that I've seen before include "More is to fit into most spacious area" , "none wider" .)