"All the world's a stage,
And all the men and women merely players:
They have their exits and their entrances;
And one man in his time plays many parts,
His acts being seven ages. At first the infant,
Mewling and puking in the nurse's arms. ..."
How Shakespeare uses it: "Puking" was first recorded in Shakespeare's "As You Like It." It was likely an English imitation of the German word "spucken," which means to spit, according to Dictionary.com.
Modern definition: A synonym for the verb "to vomit."
Source: "As You Like It," Act 2, Scene 7