1 to lose

1 to suffer from insomnia

1 to know

2 to be aware

1 to know

2 to become aware of

3 also pr. [zhī dao]

1 not known to anyone

2 secret

3 unknown

1 lit. to reply "don't know" whatever the question (idiom)

2 fig. absolutely no idea of what's going on

3 complete ignorance

1 a single slip may cause everlasting sorrow (idiom)

1 to be evident at a glance (idiom)

1 not knowing anything at all (idiom); completely ignorant

2 without an inkling

1 lit. to know one and understand half (idiom); a smattering of knowledge

2 dilettante

3 amateur