The suffix -oid, when tacked onto the end of a word (which is where all good suffixes go), means a thing similar to, resembling, like, related to or possessing the characteristics of the thing modified by the suffix. It is Latin, derived from Greek, I think (which might limit the words to which it gets appended, but not likely, these days).

(Why do I feel like the plural of suffix should be suffices?)

SciFi fans knows that an android is a thing (such as a robot) which is like a man but not a man. SciFi fans also know that a creature which is humanoid looks somewhat human but is not human. An asteroid is like a star but is not a star. Anthropoids are creatures which are like (and are related to) humans but aren't humans. I guess an alkaloid is a substance which is similar to an alka but isn't an alka.

So what's up with factoid? Following the pattern described above, a factoid should be like a fact but not a fact and therefore untrue or only partially true or almost true. But factoid is used to mean a little, curious, trivial, interesting fact. How come?