Webster's Revised Unabridged Dictionary · 1913

Seventeen

Seventeen , adjective

[Old English seventene, Anglo-Saxon seofontȳne, that is, seven-ten. Compare Seventy.]

One more than sixteen; ten and seven added; as, seventeen years.

Seventeen , noun

1.
The number greater by one than sixteen; the sum of ten and seven; seventeen units or objects.
2.
A symbol denoting seventeen units, as 17, or xvii.