Child's play

Legos are so called because the dude who invented them was a Dane and  leg godt is Danish for play well. Quite by accident, lego is also the Latin word for I build (sorta). Random Lego fact: each piece is tested to make sure it's the wrong size to get lodged in your kid's throat. 

Ouija is named for the French and German words for yes, and is Parker Brothers' trademarked name. Generic kinds are called talking boards. Anybody else find it really weird that Parker Brothers produces these things? So not a board game. Also, who the frick decided that there are magic boards that dead people can talk to you with? As Kermit the frog once said "somebody thought of that, and someone believed it." Personally, if dead people can magically move a thing on a game board, I'd think they'd be able to just, you know, write you a note.

Lincoln Logs, I just learned, are not named for Abraham Lincoln, but for the inventor's dad.

Facts gathered from Wikipedia, HowStuffWorks.com, and the great filing cabinet in my brain.