Names!

[Billeffingmurray]

Jormungandr is just another name for Midgardsormr.

I'm not saying you're wrong but I've never seen that in any translation. He is sometimes referred to as the Midgard Serpent though, so maybe sormr=serpent.

Edit: found it on wikipedia Old Norse:Miðgarðsormr
It should be noted that referring to Jormungander as Midgardsormr is kinda like referring to Odin as All Father or Thor as The charioteer. They are kind of nick names.