At

(used to indicate a point or place occupied in space); in, on, or near:
to stand at the door; at the bottom of the barrel.
(used to indicate a location or position, as in time, on a scale, or in order):
at zero; at noon; at age 65; at the end; at the lowest point.
(used to indicate presence or location):
at home; at hand.
(used to indicate amount, degree, or rate):
at great speed; at high altitudes.
(used to indicate a direction, goal, or objective); toward:
Aim at the mark. Look at that.
(used to indicate occupation or involvement):
at work; at play.
(used to indicate a state or condition):
at ease; at peace.
(used to indicate a cause or source):
She was annoyed at his stupidity.
(used to indicate a method or manner):
He spoke at length.
(used to indicate relative quality or value):
at one’s best; at cost.
be at (someone), to be sexually aggressive toward (a person):
She’s pregnant again because he’s at her morning, noon, and night.
where it’s at, Informal. the place where the most interesting or exciting things happen:
Emma says that Rome is definitely where it’s at now.
a money of account of Laos, the 100th part of a kip.
variant of ad- before t: attend.
achievement test.
antitank.
ampere-turn.
attotesla.
astatine.
atmosphere.
atomic.
attorney.
Atlantic time.
preposition
used to indicate location or position: are they at the table?, staying at a small hotel
towards; in the direction of: looking at television, throwing stones at windows
used to indicate position in time: come at three o’clock
engaged in; in a state of (being): children at play, stand at ease, he is at his most charming today
(in expressions concerned with habitual activity) during the passing of (esp in the phrase at night): he used to work at night
for; in exchange for: it’s selling at four pounds
used to indicate the object of an emotion: angry at the driver, shocked at his behaviour
(slang) where it’s at, the real place of action
noun (pl) at
a Laotian monetary unit worth one hundredth of a kip
abbreviation
Austria
Chemical symbol
astatine
symbol
Also A. ampere-turn
abbreviation
attainment target
abbreviation
Also atm. atmosphere (unit of pressure)
atomic
prep.

Old English æt, from Proto-Germanic *at (cf. Old Norse, Gothic at, Old Frisian et, Old High German az), from PIE *ad- “to, near, at” (cf. Latin ad “to, toward” Sanskrit adhi “near;” see ad-).

Lost in German and Dutch, which use their equivalent of to; in Scandinavian, however, to has been lost and at fills its place. In choosing between at church, in church, etc. at is properly distinguished from in or on by involving some practical connection; a worshipper is at church; a tourist is in the church.

The colloquial use of at after where (“where it’s at”) is attested from 1859. At last is recorded from late 13c.; adverbial phrase at least was in use by 1775. At in Middle English was used freely with prepositions (e.g. at after, which is in Shakespeare), but this has faded with the exception of at about, which was used in modern times by Trollope, Virginia Woolfe, D.H. Lawrence, and Evelyn Waugh, but nonetheless is regarded as a sign of incompetent writing by my copy editor bosses.

assimilated form of ad- “to, toward, before” before stems beginning in -t-; see ad-.

At
The symbol for the element astatine.

at- pref.
Variant of ad-.
At
The symbol for astatine.
astatine
(ās’tə-tēn’)
Symbol At
A highly unstable, rare, radioactive element that is the heaviest of the halogen elements. Its most stable isotope has a half-life of 8.3 hours. Atomic number 85; melting point 302°C; boiling point 337°C; valence probably 1, 3, 5, 7. See Periodic Table.

IBM PC AT

1. commercial at.
2. The country code for Austria.
attotesla
ampere-turn
astatine
achievement test
advanced technology
air temperature
antitank
Atlantic Time
automatic transmission
airtight
atmosphere
atomic
attorney