means A particle is a tiny, often indivisible piece of matter or energy — anything from a speck of dust to a subatomic entity like an electron.

from From Latin 'particula,' a diminutive of 'pars' (part) — literally 'a little part.' That same 'pars' fathered a whole family: 'partial,' 'partition,' 'party,' and 'parcel.' English borrowed 'particle' in the 14th century, first for any small fragment; physics only later shrank the word down to the realm of the impossibly small.