At the risk of this comment being removed for not being detailed enough, you might find more specialised responses in /r/etymology/, which specifically deals with the origins of words and their first dates of use.

The OED dates "To urinate in or on (something); to wet with urine." from the 1780s.

However, "An act of urination. Esp. in to have (also do, take) a pee." dates from the 1880s.

The definition you specifically asked about, "Urine", is dated from the mid-1950s.