Word derivation for "thirteen" :
Basque = hamahiru (from ten + three)
Finnish = kolmetoista (three + -teen)
Miresua = kiretima (three + -teen)
This is a new word. Upon consideration, I've decided to modify my Miresua conlang suffix for -teen from -taima to -tima. That means my words for eleven and twelve, which I previously posted, are no longer entirely correct, and will need to be revisited later.
The word thirteen appears once in Alice's Adventures in Wonderland.
"I'll try if I know all the things I used to know. Let me see: four times five is twelve, and four times six is thirteen, and four times seven is -- oh dear!"