particle

noun

1 minute particles of rock:

bit, tiny bit, piece, tiny piece, speck, spot, fleck, dot, atom, molecule;

mote, fragment, sliver, splinter.

2 he never showed a particle of sympathy for her:

iota, jot, whit, bit, scrap, shred, crumb, morsel, mite, atom, drop, hint, touch, trace, suggestion, whisper, suspicion, scintilla, grain, tittle, jot or tittle;

any;

Irish stim;

informal smidgen, smidge, tad;

archaic scantling, scruple.