xero / zero [zi:ro:]
xero – adj. – dry, often used as a prefix
zero – n. & v. – n. – 1. arithmetical figure “0” which denotes ‘nought’; used figuratively for nothing; v. – to set the sights using known distances or scales using known weights
Xero
Xero has come down to us from the ancient Greek for dry or withered. Unlike many terms, it has retained most of its old meaning and has similar meanings in related European languages.
Zero
Whereas the origin of xero appears straightforward, those of zero are much more complicated. Some see its beginnings in ancient Mesopotamia, some five thousand years ago. Others only look at its European existence which is much more recent. To complicate matters, it appears to have arisen independently in different regions.
As an interesting aside: Romans had no concept of zero...
When one looks to find xero in the news, either as an adjective or as a prefix, a glaring problem arises. There's a tech company named "Xero" and many of the articles refer to it and to deals it has made. To get these articles requires more careful digging. Think about where water is important.
As for zero, its presence is ubiquitous. Just think about empty spaces, space holders and soon you will find yet another one with this fascinating term and concept.