I was rather astonished to discover that a cigar is, probably, so called because it resembles a cicada. So saith the OED anyhow. You see, the Spanish for cicada is cigarra and cicadas are said to have bodies that resemble a cigar in shape.
Not being terribly familiar with cicadas (they rarely trouble the sodden residents of Clerkenwell), I had to look them up on Google and... well... have a look at that picture on the right. I can't imagine smoking such a thing by mistake.
But then, then I saw a picture of a cicada cocoon. And suddenly it all made sense. Rather strangely (to my tongue at least), cicadas are often cooked in their cocoons and eaten. Here is a picture:
It's those ones in the middle. Time for lunch, I think.
And, of course, just as a kitchenette is a little kitchen and a maisonette is a little maison, a cigarette is just a little cigar with the stress moved to the first syllable.