Usually a very early time; specifically, sunrise, but can be used to describe any ungodly-early hour. More often used by folk of rural upbringing.
We get up at the crack of dawn to feed the chickens.
a wakeup hit of rock that gets one on his/her feet and able to compete with the other urban zombies for enough cans or whatnot to afford more crack
I recognized a guy who was once a top jock at school - now, crouched behind a dumpster, smoking his crack of dawn.
What ain't safe when im horney
Im so horney that even the crack of dawn ain't safe!
1. The vagina of any woman called Dawn, or simply Dawn's crack. What you wake up to every morning if you were dating her. The cock usually crows at this time.
2. The vagina of any woman you wake up to in the morning.
3. An expression to describe when a woman's vagina is very close you your face when you wake up and it's the first thing you see.
He's normally late for work cos his cock crows every morning at the crack of Dawn.