Although I easily guessed this word from the context in which it appeared, and would perhaps recognize it in many contexts, I cannot say I would be able to recall it while writing. Notice the irony of the word’s double meaning. From Oxford American Dictionaries: An even toed ungulate mammal

In my studies I often come across words that I have heard before but I do not know the precise definition of. In many cases, the context gives me a good idea, but I find that even with words that I am very familiar with and use in my own