Sorrowful whistler secured by stake (6)
I believe the answer is:
bereft
'sorrowful' is the definition.
(similar in meaning)
'whistler secured by stake' is the wordplay.
'whistler' becomes 'ref' (a referee blows a whistle).
'secured by' is an insertion indicator (inserted letters are held or secured).
'stake' becomes 'bet' (synonyms).
'ref' inserted inside 'bet' is 'BEREFT'.
(Other definitions for bereft that I've seen before include "Deprived, of reason or loved one" , "Pained by the loss of someone" , "Having a deep sense of loss" , "Sorrowful through loss" , "Grieving from deprivation" .)