Shadow (5)
'shadow' is the definition.
(both can mean to follow someone)
This is the entire clue.
(Other definitions for tail that I've seen before include "Trail (behind comet)" , "Dog - or part of one" , "Dog - end" , "private eye" , "Rump" .)
'shadow' is the definition.
(I know that umbra is a type of shadow)
This is all the clue.
(Other definitions for umbra that I've seen before include "Burma (anag.)" , "Black spot" , "Region of shadow" , "Dark shadow cast by earth in eclipse" , "Shadow's inner region" .)
'shadow' is the definition.
(I know that penumbra is a type of shadow)
This is all the clue.
(Other definitions for penumbra that I've seen before include "Imperfect shadow" , "Area of half shade" , "Shady area" , "Outer region of shadow" , "Ring around sunspot" .)