Definition of むむ

むむ

mumu

interjection
1.
hum, hmm(onomatopia)(expressing mild surprise or doubt)
2.
hm hm (light chuckle with mouth closed)(onomatopia)
See also:ふふ
3.
uh-huh(onomatopia)(indicating agreement)
See also:うんうん
4.
mm, hmm(onomatopia)(deep in thought)
5.
well(onomatopia)(calling attention)