Straight in bath one's thrown (6)
I believe the answer is:
honest
'straight' is the definition.
(I've seen this before)
'in bath one's thrown' is the wordplay.
'in' indicates a hidden word.
'HONEST' is hidden in the letters of 'bath ones thrown'.
(Other definitions for honest that I've seen before include "Frank" , "Genuine; fair" , "Honorable, true" , "Fair and free of deceit" , "'Fair-dealing, upright (6)'" .)