13-sided solid nomenclature

Link to the appropriate column follows: http://www.straightdope.com/classics/a3_252.html

I’m afraid I must correct. The suffix -gon denotes two-dimensional shapes, as in ‘pentagon’ or ‘octagon.’ When referring to three dimensional solids, the suffix appropriate to the situation becomes -hedron (sometimes seen pluralized as -hedra, though -hedrons is preferred). So we have nonhedrons (nine-sided solids), dodekahedrons (twenty-sided solids), and thus, triskaidekahedrons (thirteen-sided solids).

–Adam, linguistics student and die collector

You may be a linguistics student, but you’re not much of geometer. The shape that the Susan B. Anthony dollar should be, but is not, is a triskaidecagonal cylinder; viewed face-on, it would be a triskaidecagon. If reckoned simply as a solid, it could be called a pentakaidecahedron, but that is less descriptive.

(Spelling such words with a “k” instead of a “c”, by the way, is good Greek, but decidedly minority English except in the metric prefix, which is officially “deka-” in the US, but “deca-” in the rest of the world.)