Hold exercise, getting the flu? (6)
I believe the answer is:
grippe
'flu?' is the definition.
(synonyms)
'hold exercise getting' is the wordplay.
'hold' becomes 'grip' (synonyms).
'exercise' becomes 'pe' (Physical Education).
'getting' says to put letters next to each other.
'grip'+'pe'='GRIPPE'
'the' is the link.
(Other definitions for grippe that I've seen before include "infection" , "'flu, as before" .)