ROGET'S THESAURUS OF ENGLISH WORDS AND PHRASES ...

Adj. flat, plane, even, flush, scutiform † , discoid; level &c (horizontal) 213; flat as a
pancake, flat as a fluke, flat as a flounder, flat as a board, flat as my hand.
252. Concavity -- N. concavity, depression, dip; hollow, hollowness; indentation,
intaglio, cavity, dent, dint, dimple, follicle, pit, sinus, alveolus † , lacuna; excavation, strip
mine; trough &c (furrow) 259; honeycomb.
cup, basin, crater, punch bowl; cell &c (receptacle) 191; socket.
valley, vale, dale, dell, dingle, combe † , bottom, slade † , strath † , glade, grove, glen,
cave, cavern, cove; grot † , grotto; alcove, cul-de-sac; gully &c 198; arch &c (curve) 245;
bay &c (of the sea) 343.
excavator, sapper, miner.
honeycomb (sponge) 252.1.
V. be concave &c adj.; retire, cave in.
render concave &c adj.; depress, hollow; scoop, scoop out; gouge, gouge out, dig,
delve, excavate, dent, dint, mine, sap, undermine, burrow, tunnel, stave in.
Adj. depressed &c v.; alveolate † , calathiform † , cup-shaped, dishing; favaginous † ,
faveolate † , favose † ; scyphiform † , scyphose † ; concave, hollow, stove in; retiring;
retreating; cavernous; porous &c (with holes) 260; infundibul † , infundibular † ,
infundibuliform † ; funnel shaped, bell shaped; campaniform † , capsular; vaulted, arched.
252a Sponge -- N. sponge, honeycomb, network; frit [Chem], filter.
sieve, net, screen (opening) 260.
Adj. cellular, spongy, spongious † ; honeycombed, alveolar; sintered; porous (opening)
260.
253. Sharpness -- N. sharpness &c adj.; acuity, acumination † ; spinosity † .
point, spike, spine, spicule [Biol.], spiculum † ; needle, hypodermic needle, tack, nail,
pin; prick, prickle; spur, rowel, barb; spit, cusp; horn, antler; snag; tag thorn, bristle;
Adam's needle † , bear grass [U.S.], tine, yucca.
nib, tooth, tusk; spoke, cog, ratchet.
crag, crest, arete [Fr.], cone peak, sugar loaf, pike, aiguille † ; spire, pyramid, steeple.
beard, chevaux de frise [Fr.], porcupine, hedgehog, brier, bramble, thistle; comb; awn,
beggar's lice, bur, burr, catchweed † , cleavers, clivers † , goose, grass, hairif † , hariff, flax
comb, hackle, hatchel † , heckle.
wedge; knife edge, cutting edge; blade, edge tool, cutlery, knife, penknife, whittle,
razor, razor blade, safety razor, straight razor, electric razor; scalpel; bistoury † , lancet;
plowshare, coulter, colter † ; hatchet, ax, pickax, mattock, pick, adze, gill; billhook,
cleaver, cutter; scythe, sickle; scissors, shears, pruning shears, cutters, wire cutters, nail
clipper, paper cutter; sword &c (arms) 727; bodkin &c (perforator) 262; belduque † ,
bowie knife † , paring knife; bushwhacker [U.S.]; drawing knife, drawing shave;
microtome [Micro.]; chisel, screwdriver blade; flint blade; guillotine.
sharpener, hone, strop; grindstone, whetstone; novaculite † ; steel, emery.
V. be sharp &c adj.; taper to a point; bristle with.
render sharp &c adj.; sharpen, point, aculeate, whet, barb, spiculate † , set, strop, grind;
chip (flint).
cut &c (sunder) 44.