Sam, it seems, is comparatively healthy (6)
This could be a double definition.
'sam' is the first definition.
(Charles Dickens character Sam Weller)
'comparatively healthy' is the second definition.
('well' can be similar in meaning to 'healthy')
'it seems is' acts as a link.
This may not be correct. Some or all of it may belong to one of the definitions.
Can you help me to learn more?
(Other definitions for weller that I've seen before include "Sam ---, Pickwick's servant", "Paul?", "Sam ---, Pickwick's man", "Sam - - ('Pickwick Papers')", "Sam -, servant to Mr. Pickwick (Dickens)".)