[合「あ」]う => To do A together/mutually N4
Secondary Verb
かも[知「し」]れない => Might A, maybe A, perhaps A N3
Sentence Endings
[一方「いっぽう」]だ => Change A continues, A does not stop N2
Miscellaneous
[一方「いっぽう」] => On one hand A, on the other, B; Although A, at the same time, B N2
Contrast,Surprise