o-

英：['əʊ]

美：['oʊ]

• [医] 正, 邻(化学)

noun (1)

the 15th letter of the English alphabet

a graphic representation of this letter

a speech counterpart of orthographic o

a graphic device for reproducing the letter o

one designated o especially as the 15th in order or class

something shaped like the letter Oespecially: zero

abbreviation (1)

ocean

ohm

old

order

over

interjection

—used to express an emotion (such as surprise or desire) or in response to physical stimuliOh, don't stop!

Oh, no! I forgot my key.

—used in direct address

oh, waiter! Will you come here, please?

—used to express acknowledgment or understanding of a statement

Oh, yes. It's one of my favorite cities.

—used to introduce an example or approximation

Their house is about, oh, I'd say four miles from here.

noun (2)

the one of the four ABO blood groups characterized by the absence of antigens designated by the letters A and B and by the presence of antibodies against these antigens

abbreviation (2)

offense

Ohio

[New Latin octarius] pint

symbol

oxygen

combining form

eggspecifically: ovum oogonium

oology

abbreviation (3)

orth- or ortho-

affix

—used as a connective vowel originally to join word elements of Greek origin and now also to join word elements of Latin or other originelastomer

speedometer

noun suffix

one that is, has the qualities of, or is associated with

bucko

interjection suffix

—in interjections formed from other parts of speechrighto

cheerio

abbreviation (3)

orth- or ortho-

affix

—used as a connective vowel originally to join word elements of Greek origin and now also to join word elements of Latin or other originelastomer

speedometer

noun suffix

one that is, has the qualities of, or is associated with

bucko

interjection suffix

—in interjections formed from other parts of speechrighto

cheerio

〔化学符号〕意为(ortho-)正，邻

Combining form Greek ōi-, ōio-, from ōion — more at egg >entry 1 Affix Greek, thematic vowel of many nouns and adjectives in combination Noun suffix perhaps from oh >entry 1 Interjection suffix probably from oh >entry 1

The first known use of o was before the 12th century

o'clockadverb

according to the clock

the time is three o'clock

—used for indicating position or direction as if on a clock dial

an airplane approaching at eleven o'clock

oceangoingadjective

made to travel on the ocean

oceangoing ships

occluded frontnoun

occlusion sense 2

occipital bonenoun

a compound bone that forms the back part of the skull

oblique anglenoun

an acute or obtuse angle

objet d'artnoun

an article of artistic value

object lessonnoun

a real example of how some general idea or role works

object1 of 2noun

something that can be perceived by the senses

I see an object in the distance

something that is the target of thought or feeling the object of my affections

an object of study

the goal or purpose of some activity

the object is to raise money

a noun or term behaving like a noun that receives the action of a verb or completes the meaning of a preposition

something (as an icon or window) on a computer screen that can be moved or used by itself

object2 of 2verb

to offer or mention as an objection

objected that the price was too high

to oppose something firmly usually with words

objected to the plan

o1 of 2noun

the 15th letter of the English alphabet

zero entry 1 sense 1

O2 of 2

o-1 of 4abbreviation

orth-; ortho-

O2 of 4noun

the one of the four ABO blood groups characterized by the absence of antigens designated by the letters A and B and by the presence of antibodies against these antigens

O3 of 4abbreviation

opening

[Latin octarius] pint—used in writing prescriptions

O4 of 4symbol

oxygen