An armature line is a foundational line within a poem that provides structural or thematic support for the entire composition, much like a metal framework (armature) supports a sculpture; this line often appears early and establishes key motifs, tonal registers, or philosophical premises that subsequent lines elaborate, refract, or contest, serving as the poem’s invisible spine and ensuring coherence even in highly fragmented or experimental forms, as seen in the opening declarations of many modernist masterpieces.

Line providing structural support or framework for surrounding lines. Architectural metaphor for load-bearing verse. Related to key line and refrain. Useful concept for analyzing poem's structural integrity.