thickening /ˈθɪkənɪŋ/noun 3adjective 1forms 1 noun3 •The process of making something, or becoming, thick or viscous. •A substance, usually a source of starch, used to thicken a sauce. •A thickened part of a structure.[…] the inner layer (of nearly equally large cells) lacks the regular semiannular or annular thickenings of most other leafy liverworts […] — 1992 adjective1 •Beginning to thicken, becoming thicker. formsthickenings
