- a combining form meaning “ten,” used in the formation of compound words: decapod.
- denoting ten: decagon . In conjunction with scientific units the symbol da is used
before a vowel, dec-, word-forming element meaning “ten,” from Latinized comb. form of Greek deka “ten” (see ten). In the metric system, “multiplied by ten;” while deci- means “divided by ten.”
- A prefix that means ten, as in decahedron, a polygon having ten faces.