Noun
なきむし
泣き虫コウちゃーん、ほら、コウちゃんの好きなトンネルだよーっ！
Hey, crybaby Ko-chan. Here comes a tunnel you like.
コウイチだけがビエトが泣き虫だということを知っている。
Only Koichi knows Viet is a crybaby.
娘の高熱が中々下がりません。普段は泣き虫なんですが、今は泣く元気も無いようで、心配です。
My daughter's high fever doesn't seem to be coming down. She is usually a crybaby, but it seems like she doesn't even have energy to cry now and I'm worried.
You've seen that 泣く is to cry, so you can probably guess that 泣き is just "cry." You've also seen how 虫 is rarely a nice thing to call someone. So what's a mean thing you can call someone who cries? How about a crybaby?
The readings come from 泣く and 虫. So long as you're okay with those two words you should be able to read this one too.