nousei

Nousei, written in kanji as 能性, is a Japanese noun that denotes an inherent capacity, potential, or tendency of a person, object, or system. It is often romanized as nōsei, though some transliterations spell it as nousei. The term emphasizes what something can become or achieve by virtue of its nature, rather than what is merely possible in general terms or what is currently actual.

Etymology and nuance: 能 means “ability” or “ability to perform,” while 性 indicates “nature,” “property,” or “quality.” Together they form a word that centers on intrinsic capacity or potential. Because of this nuance, 能性 is typically used in technical or formal contexts where internal potential is being discussed. It is distinct from 可能性 (kanōsei), which more directly means “possibility,” and from 能力 (nōryoku), which means “ability” or “capability” in the sense of skills or power.

Usage and examples: In biology and related fields, 能性 appears in compounds that express potential or potency, such as 多能性 (tanōsei, multipotency), 発生能性 (hassei-nōsei, developmental potential), or 再生能 (saiseinō, regenerative capacity). In materials science or engineering, 能性 can refer to the inherent functional properties or latent capabilities of a material or system. In everyday language, however, people more often use 可能性 when referring to general possibilities.

See also: possibility, ability, multipotency, developmental potential, regenerative capacity.