third pine; furthest pine from the Noh stage
Refers to the pine tree farthest from the stage among the three pines placed along the bridge walkway (hashigakari) in Noh theater. A domain-specific term used in discussions of Noh stage architecture and symbolism.
Along the bridge walkway of a Noh stage, the first pine, second pine, and third pine are planted.
Compound of 三 (san, 'three') + の (no, possessive particle) + 松 (matsu, 'pine'). The term is specific to Noh theater staging conventions.