Involve (6)
'involve' is the definition.
(entail means to involve or require)
This is the entire clue.
(Other definitions for entail that I've seen before include "If willing, this settles" , "settle estates for the long term" , "Invlove or necessitate" , "legal restriction" , "Need" .)
'involve' is the definition.
(I know that embroil is a type of involve)
This is the entire clue.
(Other definitions for embroil that I've seen before include "Involve (someone) in trouble" , "Involve deeply (in a difficult situation)" , "catch up" , "Implicate" , "Involve (someone) in a dispute" .)