Could be most any cucurbit.

High probability Cucumis melo

That's true. Cukes have somewhat more pointy leaves. My canteloupes and honeydews have leaves that look just like this. But squash are still a possibility.

Thank you all so much! Would love if it turns out to be any type of melon. I'm gonna plant it with plenty of space and see what comes :-)

Is this something which just popped up in the bed? Or did you plant it? If it just appeared there's no knowing what the quality will be like.

Ooh, great point, Floral. Thank you for that. Yeah, it just popped up, most likely a seed that made it through the compost process. We do eat a lot of melons. My dad is insistent on planting it (saving it), so we are going to leave things to chance on this one. But good to know, your comment is much appreciated. :-)

I had a melon sprout from the compost...took a while for the "netting" to develop to realize it was a cantaloupe. Never did get it to fully ripen before the frost hit it though.

Thanks Donna for sharing your experience :-) This one has been quite a quick grower so I'm hoping it continues that way and sets fruit throughout the spring/summer.