O, the fifteenth letter of the English alphabet, derives its form, value, and name from the Greek O, through the Latin. The letter came into the Greek from the Pho is most closely related to a, e, and u; as in E. bone, AS. bān; E. stone, AS. stān; E. broke, AS. brecan to break; E. bore, AS. beran to bear; E. dove, AS. dfe; E. toft, tuft; tone, tune; number, F. nombre. [1913 Webster]
Among the ancients, O was a mark of triple time, from the notion that the ternary, or number 3, is the most perfect of numbers, and properly expressed by a circle, the most perfect figure. [1913 Webster]

o, n.

The letter O, or its sound. Tennyson. [1913 Webster]
Something shaped like the letter O; a circle or oval. Shak. [1913 Webster]
A cipher; zero. [1913 Webster]
"Thou art an O without a figure." [1913 Webster]

o, a. [See One.].

One. [1913 Webster]

o, interj.

An exclamation used in calling or directly addressing a person or personified object; also, as an emotional or impassioned exclamation expressing pain, grief, surprise, desire, fear, etc. [1913 Webster]

" O is frequently followed by an ellipsis and that, an in expressing a wish: “O [I wish] that Ishmael might live before thee!” Gen. xvii. 18; or in expressions of surprise, indignation, or regret: “O [it is sad] that such eyes should e'er meet other object!”" Sheridan Knowles. [1913 Webster]

" A distinction between the use of O and oh is insisted upon by some, namely, that O should be used only in direct address to a person or personified object, and should never be followed by the exclamation point, while Oh (or oh) should be used in exclamations where no direct appeal or address to an object is made, and may be followed by the exclamation point or not, according to the nature or construction of the sentence. Some insist that oh should be used only as an interjection expressing strong feeling. The form O, however, is, it seems, the one most commonly employed for both uses by modern writers and correctors for the press. “O, I am slain!” Shak. “O what a fair and ministering angel!” “O sweet angel !” Longfellow." [1913 Webster]

"For ever, O Lord, thy word is settled in heaven." [1913 Webster]

"O how love I thy law ! it is my meditation all the day." [1913 Webster]

"O for a kindling touch from that pure flame!" [1913 Webster]

"But she is in her grave, -- and oh
The difference to me!" [1913 Webster]

"Oh for a lodge in some vast wilderness!" [1913 Webster]

"We should distinguish between the sign of the vocative and the emotional interjection, writing O for the former, and oh for the latter." [1913 Webster]

O dear, O dear me! [corrupted fr. F. O Dieu! or It. O Dio! O God! O Dio mio! O my God! Wyman.], exclamations expressive of various emotions, but usually promoted by surprise, consternation, grief, pain, etc.

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OXFORD DICTIONARY

o, n. (also o) (pl. Os or O's)
1 the fifteenth letter of the alphabet.
2 (0) nought, zero (in a sequence of numerals esp. when spoken).
3 a human blood type of the ABO system.

o, abbr. (also O.) Old.

o, symb. Chem. the element oxygen.

o, int.
1 var. of OH(1).
2 prefixed to a name in the vocative (O God).

Etymology

ME, natural excl.

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ROGET THESAURUS

o

Security

N security, guaranty, guarantee, gage, warranty, bond, tie, pledge, plight, mortgage, collateral, debenture, hypothecation, bill of sale, lien, pawn, pignoration, real security, vadium, stake, deposit, earnest, handsel, caution, promissory note, bill, bill of exchange, I, O, U, personal security, covenant, specialty, parole, acceptance, indorsement, signature, execution, stamp, seal, sponsor, cosponsor, sponsion, sponsorship, surety, bail, mainpernor, hostage, godchild, godfather, godmother, recognizance, deed of indemnity, covenant of indemnity, authentication, verification, warrant, certificate, voucher, docket, doquet, record, probate, attested copy, receipt, acquittance, quittance, discharge, release, muniment, title deed, instrument, deed, deed poll, assurance, indenture, charter, charter poll, paper, parchment, settlement, will, testament, last will and testament, codicil, bonis avibus, gone where the woodbine twineth.

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