めったな => hardly; rarely; seldom N2
Ban
に行く/に来る/に帰る => go/arrive/go back (to do something) N5
へ => Go to N, head to N , Often followed by verbs like 行く/いく, 来る/くる, 向かう/むかう… N5
Particles
めったに~ない => hardly; rarely; seldom N3
めったにない => Rarely N3
Degree. Level, Amount
なければならない/なくてはならない/なければいけない/なくてはいけない/なければだめ/なくてはだめ => must N5
~んがため(に)/~んがための      => in order to ~ N1
~づめだ      => full of N1
ため => In order to, for N4
Purpose, target
ないといけない / だめだ => must do; have an obligation to do ~ N4
Necessity, obligation
~ような...ような => like; as; similar to ~. N1
Speculation
ずくめ => completely; entirely; nothing but ~ N1