O grade or Ordinary grade noun

In Scotland, (a pass in) a former examination generally taken at the end of the 4th year of secondary education (also adjective, often with hyphen)

O level or Ordinary level noun

Esp in England and Wales, (a pass in) a former examination generally taken at the end of the 5th year of secondary education (also adjective, often with hyphen)

O

symbol

1. (as a medieval Roman numeral) 11
2. /ō/ oxygen (chem)

Ō

symbol

(medieval Roman numeral) 11000

O¹ or o /ō/

noun (pl Oes, Os, O's, oes or o's /ōz/)

1. The fifteenth letter in the modern English alphabet, fourteenth in the Roman, derived from Greek omicron (Ο, ο), with various sounds, as in note, not, for, work, son, do
2. One of the four blood types in the ABO blood group system
3. In a series of numbers, nought or nothing
4. (usu in pl) a spangle (obsolete)
5. Anything shaped like the letter O

ordinary /örˈdi-nə-ri, örˈd(i)n-ri, ördˈnə-ri/, Scot ordinar /ördˈnər/

adjective

1. According to the common order or type
2. Usual
3. Of the usual kind
4. Customary
5. Plain
6. Undistinguished
7. Commonplace
8. (of a judge or jurisdiction) by virtue of office, not by deputation
9. (of a judge in Scotland) of the Outer House of the Court of Session (Lord Ordinary)
10. Plain-looking (informal)
11. Of common rank

noun

1. Something settled or customary
2. The common run, mass or course
3. An ungeared bicycle with one large and one small wheel, a penny-farthing
4. One of a class of armorial charges, figures of simple or geometrical form, conventional in character (heraldry)
5. A reference book of heraldic charges
6. A rule or book that lays down the form of a religious service, esp the mass
7. An ordinary share
8. A judge acting in his own right by virtue of his office, eg an ecclesiastic such as a bishop or his deputy in ecclesiastical cases
9. A chaplain who attended those condemned to death, esp the chaplain of Newgate Prison (historical)
10. A meal provided at a fixed charge
11. A place where such a meal is provided
12. The company partaking of it (obsolete)
13. Usual fare (obsolete)

orˈdinarily adverb

orˈdinariness noun

ordinary degree same as pass degree (see under pass).

Ordinary grade noun see O grade under O (abbrev).

Ordinary level noun see O level under O (abbrev).

ordinary ray noun (physics)

In double refraction, the ray that obeys the ordinary law of refraction

ordinary seaman noun

A seaman ranking below an able seaman

ordinary shares plural noun

Shares in a company entitling the holder to the company's net profits as a dividend after preference shareholders have been paid (preferred ordinary shares have limited priority)

in ordinary

In regular and customary attendance

ordinary of the mass

The established sequence or fixed order for saying mass

out of the ordinary

Unusual