What to do when a word is not part of your vocabulary

Every now and then, I find a word that I do not know. For a normal person, it is a trip to the dictionary, for me it is a trip to OmegaWiki and often I find that the word is not yet in there.

Today it was the word cohort that I did not know. I knew it as something to do with Roman military, but it has also something to do with statistics..

I like pictures in my blogs, people playing soldiers is more fun to look at then some bar charts.
Thanks,
      GerardM