Nash pairs
A Nash pair, where Nash refers to Ogden, not John, is a pair of words that differ only by a prefix and but differ unexpectedly in meaning. An almost Nash pair is one in which one word of the pair, usually the one without the prefix, does not really exist, but can be given a (preferably humorous) definition.
So here are two examples. Carious and precarious form an example of an almost Nash pair. My late uncle, known as Baldy, whenever he heard someone claim that something was precarious would ask, with a twinkle in his eye: "And when was it ever carious?" But observe that carious could be taken to mean something that has acquired caries, in which case, precarious means the obvious thing.*
Here's the example of a real Nash pair that motivated this blog entry: When you are about to accept an invitation for a sumptuous meal, remember that it would be presumptuous to assume that you will be invited. Alternatively and less moralistically, a presumptuous meal is one cooked by a bad chef?
To end, here's the challenge. Find more Nash pairs and make them funnier!
*precarious (adj.): 1640s, a legal word, "held through the favor of another," from Latin precarius "obtained by asking or praying," from prex (genitive precis) "entreaty, prayer" (see pray). Notion of "dependent on the will of another" led to extended sense "risky, dangerous, uncertain" (1680s). "No word is more unskillfully used than this with its derivatives. It is used foruncertain in all its senses; but it only means uncertain, as dependent on others ..." [Johnson]. Related: Precariously; precariousness. Source: http://www.etymonline.com/index.php?allowed_in_frame=0&search=precarious&searchmode=none
