Great reading, learned new words; aphasia, lethologica, anomia and dysnomia. As well as that replete term ‘tip-of-the-tongue phenomenon’
…but surely the answer is supercalifragilisticexpealadocious
It should at least get a mention i reckon! 
-m0r
Welcome to the SDMB, m0r1arty.
It is appreciated if when you comment on one of Cecil’s columns, you provide a link to the column, if the column is online. Doing so can be as simple as pasting the URL into you post. Like so: http://www.straightdope.com/classics/a961213.html
brainfart? 
brainfart is a little too broad, in my opinion. Everything from tying your shoe wrong to leaving your keys in the door gets covered by brainfart.
Anecdote alert!!
My Dad has a nasty habit when he can’t think of a word. He stops the entire conversation and spends the next five minutes getting more and more agitated and has been known to work himself up to the point of swearing while saying something like, “what is the word for that god dman thing the mouse sits on.”
At first, my brother and I would fill in the word: “You mean mouse pad?” Then we started playing a game, “…Computer appurtenances for $200!”
We called the game, Senior Moment Jeopardy.
Cognitive psychologists actually refer to this as the Tip of the Tongue (TOT) phenomenon, http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11150221&dopt=Abstract; http://www.wjh.harvard.edu/~caram/PDFs/1997_Miozzo_Caramazza_JEP.pdf; http://psychiatry.ucsd.edu/tamargollan2.html
or sometimes aphasia. But aphasia is a diagnosis for a cluster of problems that may or may not include tip of the tongue phenomenon as a symptom. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=954449&dopt=Abstract; http://strokesupport.com/info/aphasia/what_aphasia_is.htm; http://www.mercksource.com/pp/us/cns/cns_hl_dorlands.jspzQzpgzEzzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_a_52zPzhtm.