: the smallest particle of an element that can exist alone or in combination <carbon atoms>
: a tiny particle :bit<“I don't believe there's an atom of meaning in it.” — Lewis Carroll, Alice's Adventures in Wonderland>
Word History of ATOM
The English word atom came from a Greek word atomos, meaning “not able to be divided.” Ancient Greek philosophers believed that matter could only be divided to the very smallest particles, atoms, which could not be further divided. Modern science revived the atom idea, but it was discovered that even atoms could be split, and that doing so produced great amounts of energy.
Medical Definition of ATOM
: the smallest particle of an element that can exist either alone or in combination