Looks over vessel contained by another (5)
I believe the answer is:
scans
'looks over' is the definition.
(I've seen this in another clue)
'vessel contained by another' is the wordplay.
'vessel' becomes 'can' (type of container).
'contained by' means one lot of letters goes inside another.
'another' becomes 'ss' (I am not sure about this - if you are sure you should believe this answer much more).
'can' inserted inside 'ss' is 'SCANS'.
Can you help me to learn more?
(Other definitions for scans that I've seen before include "Glances over" , "CAT and PET" , "medical examinations" , "CAT and MRI" .)