<i>
proper noun</i>
<b>J</b>ensen Ackles * <b>J</b>ared Padalecki = <b>J</b>Squared
This word stems from the SPN fan
community.
It is a term that is often used in
connection with slash fanworks. In literary works of the RPS category the abreviation for the pairing Jensen/Jared is JSquared.