(n.) A particle; a minute part; a jot; an iota.

ace atom birthmark bit blaze blemish blotch brand caste mark check checkmark cicatrix crumb cut dab dapple diacritical mark discoloration dole dot dram dribble driblet drop droplet dwarf earmark end stop engraving farthing fleck flick flyspeck fragment freckle gash gnat gobbet grain granule graving groat hack hair handful iota jot lentigo little little bit lota macula mark marking microbe microorganism midge minim minimum minutia minutiae mite modicum mole molecule mote mottle nevus nick notch nutshell ounce particle patch pebble pinch pinhead pinpoint pittance point polka dot prick punctuation punctuation marks puncture reference reference mark scar scarification score scotch scrap scratch scratching scruple smidgen smitch snip snippet speck speckle splash splotch spoonful spot stain stigma stop strawberry mark tattoo tattoo mark thimbleful tick tiny bit trifling amount trivia vanishing point watermark whit