Points to strange fluid (5)
I believe the answer is:
serum
'fluid' is the definition.
(I have seen 'Watery fluid ' mean 'serum' so perhaps 'fluid' could also mean 'serum')
'points to strange' is the wordplay.
'points' becomes 'se'.
'to strange' becomes 'rum' (similar in meaning).
'se'+'rum'='SERUM'
(Other definitions for serum that I've seen before include "Liquid separating from coagulating blood" , "Watery fluid from animal tissue" , "Antitoxin derived from blood" , "Amber-coloured fluid in the blood" , "potential shot in the arm?" .)