Context #1:
I’m so hungry! Let’s get out of here and get some grub!
Context #2:
I’m so hungry! I could grub on just about anything right now!
Explanation:
the word grub can be used as a noun or a verb.
In noun form, it means food.In verb form, it means eat.
In example 1, grubis used as a noun. “Let’s get out of here and get
some food“
In example 2, grub onis used as a verb. “I could eatjust about anything..!”
