Where does Junkrat's RIP-Tire name come from?

It's a pun on both "rip tide" and "ripcord", the cord pulled the start the tire, with "RIP" being capitalized as in "rest in peace".

I'd disagree with the other answer and suggest it's a pun on 'rip-cord', the cord you pull to open the parachute, or I've known it as the cord you pull to start a (for example) lawnmower motor (though I can't find any references to that online). Wikipedia also suggests it's the term for the thing you pull to start a Beyblade spinning. Given that Junkrat pulls some kind of cord to start the RIP-Tire like he's starting a motor it seems to reference one of the above.