a minute portion, piece, fragment, or amount; a tiny or very small bit

a particle of dust; not a particle of supporting evidence.

Physics .

one of the extremely small constituents of matter, as an atom or nucleus.

an elementary particle, quark, or gluon.

a body in which the internal motion is negligible.

a clause or article, as of a document.

Grammar .

(in some languages) one of the major form classes, or parts of speech, consisting of words that are neither nouns nor verbs, or of all uninflected words, or the like.

such a word.

a small word of functional or relational use, as an article, preposition, or conjunction, whether of a separate form class or not.

Roman Catholic Church . a small piece of the Host given to each lay communicant in a Eucharistic service.

noun

bit , crumb , dot , dribble , drop , fleck , fragment , grain , hoot * , iota , jot , minim , mite , modicum , molecule , morsel , mote , ounce , ray , scrap , scruple , seed , shred , smidgen , smithereen , speck , spot , stitch , whit , dab , dash , dram , ort , tittle , trifle , ace , anion , atom , element , granule , ion , monad , pellet , piece , trace