I overslept. / to stock up on ~

-Where have you been?

-Sorry, boss. I overslept.

-Okay?

-It won't happen again.

 

This is a diffient from "I slept in", which means I slept long well. 

I overslept. = I woke up late. 

 

/

 

-What are you getting at the store?

-I gonna stock up on water. / soymilk / dog food / detergents / toilet paper

(= I am going to stock up on ~) 

-What about cookies? 

-Those, too.