plassein

Plassein is an Ancient Greek verb meaning to mold, shape, or form. In classical usage it describes the act of shaping materials such as clay or metal, as well as the shaping of objects, plans, or even characters. The present infinitive is πλάσσειν (plássein), with related forms including ἔπλασα (“I formed”) and the participial and adjectival derivatives πλαστός (“formed, molded”) and πλαστικός (“able to be molded” or “plastic”). The sense centers on imparting a definite form to something else.

Etymology and derivatives: Plassein lies at the root of a family of Greek and later European terms related to form and molding. The adjective πλαστικός and the noun πλαστός contributed to the modern English word plastic, via Latin plastica and French plastique, all preserving the notion of moldability. The concept of plasticity, meaning the capacity to be deformed and to retain a new shape, also derives from the same Greek lineage.

Usage and context: In ancient texts, plassein covers practical crafts such as pottery, sculpture, and metalworking, as well as figurative shaping—forms, plans, or laws shaped into their intended character. In later science and philosophy, the idea extends beyond craft to describe the ability of substances or systems to adopt or retain forms under stress, a notion central to materials science and related fields.

See also: Plastic, Plasticity, Plastikos.