It is from a Latin word of the same spelling, literally meaning 'elbow. This is related to an Old English word 'eln'.
olecranon process of ulna
I've bruised my ulna.
Ulna
The ulna is one of the two long bones in the forearm.
unimaginable
spanish
coupa
The origin of a word indicates the language the word originally came from, or the languages certain parts (such as prefixes and suffixes) come from.
Chanteuse is a word of French origin.
The word is of Sanskrit origin meaning 'peace'
None, since there is no such word as "radious". Radius, however, come from Latin.
It is latin in origin.