At sea (4)
'at sea' is the definition.
(at sea can mean in lost or in confusion)
This is all the clue.
(Other definitions for lost that I've seen before include "Missing" , "TV series!" , "See 10" , "TV show" , "confused" .)
(Other definitions for saps that I've seen before include "Enervates in spas" , "Weakens, undermines" , "mugs" , "Drains energy from" , "Coshes" .)