Thiknesse

Part of speech: noun

Definitions

1. The measured distance through an object from one surface to the opposite one, or the quality of being thick in this way
2. The extent to which something is thick, measured as the space between its two opposite faces or sides
3. How thick a physical object is, meaning the dimension between its outer surfaces and the solidity this gives it

Etymology: "Thiknesse" is a Middle English spelling of what is now "thickness," and it shows how the word was once built. The base is "thick," from Old English "þicce," which is related to "thick" in other Germanic languages and probably goes back to a root meaning "dense" or "crowded together." Middle English speakers added the suffix "-nesse," an Old English noun-forming ending (the ancestor of modern "-ness") that turns an adjective into a noun for a quality, as in "goodnesse" for goodness or "sweetnesse" for sweetness. Because "-nesse" was a productive suffix, English speakers could attach it to almost any adjective, which is why the pattern is so familiar today. The spelling "thiknesse" appears in Middle English texts from roughly the fourteenth and fifteenth centuries, and the modern spelling "thickness" settled in during the following centuries as English spelling became more standardized. The "-nesse" ending gradually shortened to "-ness" as the final vowel stopped being pronounced.