Scler

Scler is a combining form derived from the Greek skleros, meaning hard. It is used in a wide range of scientific terms to denote hardness, rigidity, or thickening of tissues, cells, or structures. In contemporary terminology, the form appears in two common spellings, scler- and sclero-, depending on phonetic and etymological context.

In medicine and biology, scler- appears in terms describing disease processes or tissue properties. Sclerosis denotes abnormal hardening of tissue, as in atherosclerosis (hardening of arteries) or hepatic sclerosis. Scleroderma is a systemic connective tissue disease characterized by thickening and hardening of skin and other tissues. Scleritis refers to inflammation of the sclera, the outer white layer of the eye.

In botany and plant science, the root also appears in descriptions of hard plant tissues. Sclerenchyma and sclereids are thick-walled cells that provide rigidity to many plant parts, and the term sclero- denotes hardness in such structures. Sclerotium is a hardened resting mass formed by some fungi and oomycetes; related terms such as sclerotial bodies are used in pathology and taxonomy. Sclerotinia is a genus named for these distinguishing sclerotial structures.

Etymology and usage notes indicate that scler- and sclero- are interchangeable in many modern medical coinages, with the form chosen to suit phonology and classical roots. They function as prefixes or combining forms rather than independent words.