prefix
Prefix used in a limited set of words to indicate narrowness, thinness, or smallness. Not freely productive; appears mainly in established compounds like 狭霧 (さぎり, mist) or 狭間 (さま, gap).
「狭霧」の「狭」は、細かい霧を表す接頭語です。
The 狭 in 狭霧 is a prefix expressing fine mist.
古語では「狭」を「さ」と読み、狭いことを示す接頭語として使われた。
In classical Japanese, 狭 was read as さ and used as a prefix meaning narrow.
The prefix さ (狭/小) is of native Japanese origin, related to the adjective 狭い (せまい, narrow) and the noun 狭 (せま, narrowness). The exact historical derivation is uncertain, but it appears in Old Japanese compounds.