n. 25B6; noun
a lump of coal : CHUNK, hunk, piece, mass, block, wedge, slab, cake, nugget, ball, brick, cube, pat, knob, clod, gobbet, dollop, wad; informal glob; N. Amer. informal gob.
a lump on his head : SWELLING, bump, bulge, protuberance, protrusion, growth, outgrowth, nodule, hump.
25B6; verb it is convenient to lump them together : COMBINE, put, group, bunch, aggregate, unite, pool, merge, collect, throw, consider together.