Words can become endangered species and everyday many English words float into obscurity.
As a child, I took it upon myself to teach my younger brother (four and a half years younger, that is) a new word. Continuing our long love of words, as teenagers, my mother would share one new word per day (I think she had a web-service that emailed her the word, its origin and its meaning daily) over dinner and challenge us to put it to use.
This website, Save the Words, offers a similar challenge: adopt a word that is at risk of becoming obsolete/forgotten and use it to assist in maintaining its relevance. The idea is that when others hear it they too will commit it to memory and the word will be saved from endangerment. The site asks you select one word, and promise to use that word as often as possible. Some such words available for adoption, you ask? Solennial (meaning annually), brochity (meaning crooked teeth) and odynometer (meaning a measurement for pain).
Interestingly, in typing this entry, the only words that my spellchecker has flagged are those three words ripe for adoption... sounds like proof of their worthiness to me.