yksipäistä

Yksipäistä is an adjective in Finnish meaning having one head or possessing a single head. It is the partitive singular form of the base adjective yksipäinen, used when describing a noun in partitive case, for example in phrases like yksipäistä olentoa.

Grammatically, yksipäinen is a -inen adjective and follows the typical declension pattern of such adjectives. The nominative singular form is yksipäinen, the nominative plural is yksipäiset, the partitive singular is yksipäistä, and the partitive plural is yksipäisiä. The form yksipäistä signals that the adjective modifies a noun in the partitive case or appears in a construct requiring partitive, often in descriptive or hypothetical contexts.

Usage of yksipäistä is relatively specialized. It tends to appear in descriptive, scientific, or fictional texts rather than in everyday speech. It may describe animals, beings, or figures imagined to have a single head, or be used metaphorically to denote unity of leadership or form in a figurative sense.

Etymology is straightforward: it derives from the numeral yksi (one) and the noun pää (head), with the adjective suffix -inen added to form a descriptive adjective. Related terms include kaksipäinen (two-headed) and kolmikantinen variants for other head-count descriptions.

See also: kaksipäinen, kolmisilmäinen (where relevant), Finnish adjective declension, Finnish partitive case.