What does thickness mean?
Thickness is the noun used to describe how thick something is, particularly when that extent can be measured. It commonly refers to the distance between two surfaces, as in the thickness of a wall, sheet of metal, or layer of paint. The word can also identify a particular layer or amount of material, such as a thickness of frost or a thickness of pastry. In everyday use, thickness often carries a practical association: a material may be selected for its thickness, measured for its thickness, or criticized for being insufficiently thick. It is therefore broader than a simple physical dimension, since it can describe both a measurable property and the quality of being thick. Thickness is most useful when precision matters, distinguishing one material or layer from another according to depth, weight, or degree. It is used in British and American English and is especially familiar in construction, engineering, cooking, textiles, and manufacturing.
nounThe degree to which something is thick, especially the measurable distance between two surfaces. It can also refer to a layer or amount of material with a specified thickness.
- The measurable degree of thickness possessed by an object or material.
- A layer, coating, or amount of material with a specified thickness.
"Measure the thickness of the wall before drilling into it."
"The thickness of the fabric varies slightly along the seam."
"A thin layer of frost had formed on the windows."
Usually uncountable when referring to the general property of being thick or a single measured dimension. The plural is uncommon but standard when referring to several distinct layers or measurements.
"The different thicknesses of the sheets affect how quickly the heat transfers."
Thickness is where “thick” becomes a number: a material's thickness can be specified in millimetres, inches, or points.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does thickness come from?
Thickness is formed in English from thick and the productive suffix -ness, which turns a quality into a noun naming that quality. Its Middle English form was thiknesse, used for the state or degree of being thick, and it continues the older English word-forming pattern represented in Old English. Related Germanic words reflect the same broad root, including German Dicke and Dutch dikte. English also developed forms such as thicken and thickly from the same base adjective.
How thickness is actually used
Usually neutral and factual. It is especially common in technical, manufacturing, construction, cooking, and textile contexts. As a count noun, it usually refers to distinct layers or thicknesses.
Easily confused with thickness
Thickness is a measurement or degree of being thick, whereas a thicket is a dense group of trees, shrubs, or other plants.