A Defining Day (Dictionary Day)

What do the words entredentolignumologist, oxyosphresia,and zygodactyl have in common? I don't know what any of them mean. But, thanks to a Mr. Noah Webster (who's birthday in 1758 fell on this day), there are ways to remedy my ignorance.

Go ahead. I know you're curious to look those words up. You're a word master, it's what you do. Honor Mr. Webster himself by using promotional Webster's Dictionaries. If you're not convinced, consider this: without the advent of the Dictionary, we would never have been introduced to the game Pictionary, and honestly, what's better than Pictionary?