The inability to recall a precise word for something or to articulate thoughts. Listed as a psychological disorder, apparently the American Psychiatric Association has stated that 9 out of 10 Westerners will suffer some form of lethologica during their lifetimes.
Etymology: Latin; letho forgetfulness + logica logic
Google won't help you
Without a nice searching word.
This weekend is the 90FM trivia contest ("the world's largest trivia contest"), which runs 54 hours straight. We've just finished hour 35.
I slept for about 5 hours Saturday evening, so I am still mostly able to form complete sentences. However, as a general rule, it's unwise to post during the latter hours of the contest.