凍いつ

nidan verb (lower class) with 'tsu' ending (archaic), intransitive verb

to freeze

Archaic intransitive verb (Nidan, lower class, -tsu ending). Modern equivalent is 凍てる (いてる) or 凍る (こおる). Found only in classical texts.

See also: 凍てる

• 古こ語ごでは「水みずが凍いつ」のように用もちいた。

  In classical Japanese, it was used like 'the water freezes'.