A consensus is an agreement, but in the sense of the majority of a group having a particular opinion rather than something like a formal vote or contract. It has nothing to do with 'census', although it sounds like it: both have the sibilant '-s-' sound. (See soft c.) Consensus is derived from the Latin con meaning 'with' and sensus ('feel'); the general meaning is then 'the feeling shared [by those present]'. Census is derived from another Latin word, censere, which means 'to rate, estimate or evaluate': it was originally applied to taxation and has only come to mean 'counting the population' since the eighteenth century.
Consensus is commonly misspelled. It has three 's's, and its only 'c' comes at the beginning.
- The spelling of words, you may note, is really nothing more than a consensus. There's often little reason or logic to it, and the way words are spelled is often an accident of history and etymology. But most people agree on a particular spelling, and so it stays.
This page was suggested by the list of "25 of the most commonly misspelled words in the English language", in the article on "spelling" in Garner, Bryan A., The Oxford Dictionary of American Usage and Style, Oxford University Press, 2000; on line at Oxford Reference Online. Oxford University Press, under licence to Hull University. 18 July 2006. <http://www.oxfordreference.com/views/ENTRY.html?subview=Main&entry=t26.e2017>.
AWE shares the confidence of that article: "Naturally, they're spelled correctly here".