thermical

Thermical is an adjective used to denote relation to heat or temperature. In modern English it is rare and often regarded as archaic or nonstandard. It appears in older scientific texts and some translations; contemporary writers typically substitute "thermal" or "thermic" depending on the context.

Etymology and relation to other terms: The form derives from the root therm- from Greek therme meaning heat, with the adjectival suffix -al. Because its precise historical usage varies and it is seldom employed in current technical writing, many dictionaries classify thermical as obsolete or regional.

Usage guidance: For general heat-related properties, processes, and measurements, the preferred terms are "thermal" (thermal energy, thermal conductivity, thermal expansion). For physiological or energy-expenditure contexts involving heat generation or exchange, "thermic" is common (thermic effect of food, thermic regulation). Thermical may appear in some historical descriptions or in translations, but modern authors would normally rewrite such passages as thermal or thermic.

Limitations: Because thermical is not widely used today, relying on it can cause ambiguity or misinterpretation. When documenting or discussing heat-related phenomena, adopting the standard terms thermal or thermic improves clarity and alignment with accepted scientific vocabulary.