Frustrated (6)
'frustrated' is the definition.
(I know that frustrated can be written as foiled)
This is all the clue.
(Other definitions for foiled that I've seen before include "Thwarted with sword?" , "Prevented the success of" , "Thwarted, frustrated" , "Thwarted, defeated" .)
'frustrated' is the definition.
(dash can mean to ruin or frustrate a plan)
This is the entire clue.
(Other definitions for dashed that I've seen before include "Ran; blooming" , "Thrown to the ground, as hopes may be" , "Threw down or ran fast" , "Confounded" , "Ran hastily" .)