What is the meaning of ау?

trap, snare

net, dragnet, seine

spiderweb, cobweb

hunt, hunting expedition

fishing net

hunt, hunting expedition

ah, oh

oh my

ow, ouch

voice

sound

there, within that area (far away from here)

but

huh? (used as a response to one's name being called or to indicate not quite having heard something)

hello? (is anyone there?)

hunt

net

Source: wiktionary.org