adj., n., & adv.
--adj.
1. a of great or specified extent between opposite surfaces (a thick wall; a wall two metres thick). b of large diameter (a thick rope).
2 a (of a line etc.) broad; not fine. b (of script or type, etc.) consisting of thick lines.
3 a arranged closely; crowded together; dense. b numerous (fell thick as peas).
4 (usu. foll. by with) densely covered or filled (air thick with snow).
5 a firm in consistency; containing much solid matter; viscous (a thick paste; thick soup). b made of thick material (a thick coat).
6 muddy, cloudy; impenetrable by sight (thick darkness).
7 colloq. (of a person) stupid, dull.
8 (of a voice) indistinct.
9 colloq. intimate or very friendly (esp. thick as thieves).
--n. a thick part of anything.
--adv. thickly (snow was falling thick; blows rained down thick and fast).
Phrases and idioms:
a bit thick Brit. colloq. unreasonable or intolerable. in the thick of
1. at the busiest part of.
2 heavily occupied with. thick ear Brit. sl. the external ear swollen as a result of a blow (esp. give a person a thick ear). thick-skinned not sensitive to reproach or criticism. thick-skulled (or -witted) stupid, dull; slow to learn. through thick and thin under all conditions; in spite of all difficulties.
Derivatives:
thickish adj. thickly adv.
Etymology: OE thicce (adj. & adv.) f. Gmc