fundamental particle

/F AH0 N D AH0 M EH1 N T AH0 L P AA1 R T AH0 K AH0 L/
noun
  1. 1

    Any of the subatomic particles that does not consist of other, smaller particles; the gauge bosons, leptons and quarks.

Source: https://en.wiktionary.org/wiki/fundamental%20particle