(もくてき) The reason you’re doing something – “I’m seeing this movie because I want to have an excuse to say hi to the cute usher.”   $$$
(どうき) Motive – usually used when talking about crimes.
(もくひょう) A goal – usually not something you do all in once. Usually related to self-improvement in some way. “My goal is to learn French in 2 years.” “My goal is to run a marathon next July.”
(ねらい) Your aim – sounds like hunting.
(いと) Intention. Usually used like this:“Ahahaha! Just as I’d intended!” Or, “You did that on purpose! You did that intentionally!”  or, “She came here with the intention of stabbing the possum!”
(xxxめあて) Hidden motive or ultimate (i.e. final) purpose. Usually used like, “金目当て女“。