(idiomatic) In the middle of (something difficult).

Obsolete spelling of thick

(simile) Very stupid; slow to learn or understand.

Both thickets and thin woodland; (through) all obstacles in a path. / (idiomatic) Both good and bad times.

Having a thick skin. / Not easily offended. / Insensitive to the feelings of others; callous. / (obsolete) Obtuse, thick, intellectually dull or insensitive.

(idiomatic, simile, of friends or members of a group) Intimate, close-knit, tight.

(simile, Scotland) Very stupid

(nautical) All plank that is more than four inches thick and less than twelve.

(chiefly Britain, dated) High tea or an informal late afternoon or early evening meal, more substantial than afternoon tea. / Used other than figuratively or idiomatically: see thick, tea.

(simile, informal) Very stupid.