A lot vs. Alot: 9 Grammatical Pitfalls
blood type, 1926, originally "zero," denoting absence of A and B agglutinogens.
as a prefix in Irish names, from Irish ó, ua (Old Irish au) "descendant."
The Greek letter omicron. Entries beginning with this character are alphabetized under omicron.
The symbol for the element oxygen.
ortho- (often italic)
Used as a connective to join word elements: acidophilic.
omicron om·i·cron (ŏm'ĭ-krŏn', ō'mĭ-)
Symbol o The 15th letter of the Greek alphabet.
The symbol for oxygen.
A nonmetallic element that exists in its free form as a colorless, odorless gas and makes up about 21 percent of the Earth's atmosphere. It is the most abundant element in the Earth's crust and occurs in many compounds, including water, carbon dioxide, and iron ore. Oxygen combines with most elements, is required for combustion, and is essential for life in most organisms. Atomic number 8; atomic weight 15.9994; melting point -218.4°C; boiling point -183.0°C; gas density at 0°C 1.429 grams per liter; valence 2. See Periodic Table.
Our Living Language : In 1786, the French chemist Antoine Lavoisier coined a term for the element oxygen (oxygène in French). He used Greek words for the coinage: oxy- means "sharp," and -gen means "producing." Oxygen was called the "sharp-producing" element because it was thought to be essential for making acids. Lavoisier also coined the name of the element hydrogen, the "water-producing" element, in 1788. Soon after, in 1791, another French chemist, J. A. Chaptal, introduced the word nitrogen, the "niter-producing" element, referring to its discovery from an analysis of nitric acid.
[1960s+; fr a humorous imitation of Spanish or Italian words, more probably Spanish because of the similar el -o pattern of coinage]