- nub, nubble - a small lump or protuberance
--1 is a kind of bulge, bump, hump, gibbosity, gibbousness, jut, prominence, protuberance, protrusion, extrusion, excrescence
- nub, stub - a small piece; "a nub of coal"; "a stub of a pencil"
--2 is a kind of part, piece
--2 has particulars: nubbin - kernel, substance, core, center, essence, gist, heart, heart and soul, inwardness, marrow, meat, nub, pith, sum, nitty-gritty - the choicest or most essential or most vital part of some idea or experience; "the gist of the prosecutor's argument"; "the heart and soul of the Republican Party"; "the nub of the story"
--3 is a kind of content, cognitive content, mental object
--3 has particulars:bare bones; hypostasis; quiddity, haecceity; quintessence; stuff