Parasite caught in part of foot when getting up (5)
I believe the answer is:
leech
'parasite' is the definition.
(synonyms)
'caught in part of foot when getting up' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'in' means one lot of letters goes inside another.
'part of foot' becomes 'heel' (heel is a part of the foot).
'when getting up' is a reversal indicator.
'c' inserted inside 'heel' is 'hceel'.
'hceel' reversed gives 'LEECH'.
(Other definitions for leech that I've seen before include "Old doctor" , "Medicinal bloodsucker" , "sponge" , "Bloodsucking annelid" , "Sucking parasite" .)