Meaning of ATOM in English

ATOM

ˈad.əm, ˈatəm noun

( -s )

Usage: often attributive

Etymology: Middle English atome, from Latin atomus, from Greek atomos, from atomos indivisible, from a- a- (II) + tomos, verbal of temnein to cut — more at tome

1. philosophy

a. : one of the minute, indivisible, discrete, and concrete particles of which according to ancient materialism the universe is composed ; often : a similar particle considered as being of the stuff of which the mind is composed

b. : one of the various final irreducible or basic units or constituents of which according to different theories the universe is ultimately constructed (as minute things or processes in physicalistic theories and presentations or sense qualia in phenomenalistic theories) ; often : a logical construct that is formed from such basic units

c. : a particular or an element that is considered to be ultimate or unanalyzable for the purposes of a given system

2.

a. : a tiny particle : mote , bit

atoms of dust dancing in the sunlight

the glass bowl was smashed to atoms

b. : the smallest possible part : minute fragment : tiny portion or quantity

not an atom of water to drink

without an atom of common sense

c. : a very small creature or object : mite

brilliant hummingbirds, flashing atoms of color

d. : a small individual unit usually viewed as a relatively independent member of a group

every man is a social atom

3.

a. according to the atomic theory : the smallest particle of an element that can exist either alone or in combination with similar particles of the same or of a different element : the smallest particle of an element that enters into the composition of molecules — see atomic theory 2

b. : a group of such particles constituting the smallest quantity of a radical

an atom of ammonium

c. : molecule — used especially in earlier literature

d. : a quantity proportional to the atomic weight : the atomic weight in grams : gram atom

4. : the atom considered as a source of vast potential destructive or constructive energy

attempts to use the atom in peacetime projects

especially : the atom as the core nucleus of the fission bomb

trying to defend our cities against the atom

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.