thick

The word “thick” means having a large distance between opposite surfaces; not thin. In plain terms, not thin — whether that means wide, dense, syrupy, hard to see through, or (informally) a bit slow-witted.

“Thick” is pronounced thihk (/θɪk/ in IPA).

Here is “thick” used in a sentence: “She spread a thick layer of jam on the toast.”

“Thick” is an adjective.

The word “thick” comes from Old English. From Old English þicce ("thick, dense"), part of a very old Germanic word family — related to Dutch dik and German dick.

“Thick” is a fairly common word in modern English, usually learned at around the A1 level.

“Thick” has 7 distinct senses listed in this dictionary. The most common is: having a large distance between opposite surfaces; not thin.

Thickness measures the distance through an object, between its two opposite surfaces, while width measures the distance across it from side to side. A plank can be wide but not thick, meaning broad across yet shallow front to back. Thick always refers to how deep or substantial something is through its body.

Thick describes a large distance between surfaces or, for liquids, a heavy consistency that flows slowly. Dense describes how tightly packed the matter is, or how much mass fits in a space. A thick fog is deep and hard to see through; a dense fog is heavily concentrated. They often overlap but aren't identical.

Beyond measuring distance between surfaces, 'thick' describes viscous liquids (thick soup), heavy concentrations (thick smoke or a thick crowd), and close friendship (thick as thieves). Informally in British English it can also mean slow-witted. All these senses share the idea of something substantial, heavy, or densely gathered.

The standard opposite is thin, for something with little distance between its surfaces. For liquids the opposite is runny or watery; for fog or crowds it is sparse or light; for consistency, fine. Which antonym fits depends on whether you mean a solid object, a fluid, or a gathering.