Check out from hospital catching cold (4)
I believe the answer is:
scan
'check out' is the definition.
(thesaurus)
'hospital catching cold' is the wordplay.
'hospital' becomes 'san' (I've seen this in other clues).
'catching' means one lot of letters goes inside another.
'cold' becomes 'c' (eg on taps).
'san' placed around 'c' is 'SCAN'.
'from' is the link.
(Other definitions for scan that I've seen before include "Study systematically" , "Examine closely to analyse metrically" , "Read electronically" , "Peruse, scrutinise" , "Skim; examine" .)