Took a risk (7)
(Other definitions for gambled that I've seen before include "Took a punt" , "Took a chance" , "Wagered" , "Made a bet" , "Speculated - took chances" .)
'took a risk' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dared that I've seen before include "Ventured" , "Was brave enough" , "Risked" , "Challenged (to a deed)" , "Defied, challenged" .)