Synonyms for Thin (same or very similar meaning)
WordNet sense 1 (having low density):
rare, rarefied
WordNet sense 2 (having thin consistency):
tenuous
WordNet sense 3 (having little width in proportion to the length or height):
slender
WordNet sense 4 (very thin and insubstantial):
flimsy, light
WordNet sense 5 (thin in thickness or diameter):
fine, fine
WordNet sense 6 (so thin as to transmit light):
diaphanous, gossamer, sheer, transparent
WordNet sense 7 (flattened laterally along the whole length (e.g., certain leafstalks or flatfishes)):
flat
WordNet sense 8 (having little physical or spiritual strength):
weak
WordNet sense 9 (lacking ardor or vigor or energy):
spiritless
WordNet sense 10 (not wide):
narrow
WordNet sense 11 (thin and fit):
spare, trim
WordNet sense 12 (being of delicate or slender build):
slight, slim, svelte
WordNet sense 13 (lean and wrinkled by shrinkage as from age or illness):
shrunken
WordNet sense 14 (being very thin):
scrawny, skinny, scraggy
WordNet sense 15 (resembling a reed in being upright and slender):
reedy
WordNet sense 16 (having a lean and bony physique):
rawboned
WordNet sense 17 (long and lean):
lank, spindly
WordNet sense 18 (tall and thin):
lanky
WordNet sense 19 (very thin especially from disease or hunger or cold):
bony, emaciated, gaunt, haggard, pinched, skeletal, wasted
WordNet sense 20 (lacking excess flesh):
lean
WordNet sense 21 (not dense):
sparse
WordNet sense 22 (spread out or scattered about or divided up):
distributed
WordNet sense 23 (without viscosity):
thinly
WordNet sense 24 (lessen the strength or flavor of a solution or mixture):
cut, dilute, reduce, thin out
WordNet sense 25 (take off weight):
slenderize, lose weight, melt off, slim down
From the ODE community, based on WordNet
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