Nail down (6)
'nail down' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ensure that I've seen before include "warrant" , "Make certain, secure" , "Protect" , "Make certain or safe" , "Make certain (something will occur)" .)
'nail down' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for set that I've seen before include "Solidify; group" , "Cake < , plonk < , something served" , "Prepared" , "Fix in place; similar group" , "Mount (precious stone)" .)