Noun: atom a-tum
- (physics and chemistry) the smallest component of an element having the chemical properties of the element
"The scientist explained that water molecules consist of two hydrogen atoms and one oxygen atom"
- (nontechnical usage) a tiny piece of anything
"Not an atom of truth remained in his story";
- molecule, particle, corpuscle, mote, speck
Derived forms: atoms
Type of: material, stuff, substance
Part of: chemical element, element, molecule
Encyclopedia: Atom