The Collaborative International Dictionary
Purlin \Pur"lin\, Purline \Pur"line\, n. [Etymol. uncertain.] (Arch.) In roof construction, a horizontal member supported on the principals and supporting the common rafters.
Wiktionary
n. A longitudinal structural member bridge#Verb two or more rafter of a roof.
Wikipedia
In architecture, structural engineering or building, a purlin (or historically purline, purloyne, purling, perling) is any longitudinal, horizontal, structural member in a roof except a type of framing with what is called a crown plate. In traditional timber framing there are three basic types of purlin: purlin plate, principal purlin and common purlin.
Usage examples of "purlin".
The Mountaineer Lodge was an imposing fretwork of rafters, joists, beams, and purlins slotted together with hand-tooled joints: a modern version of the pioneer cabin, expanded to accommodate fifty guests in neo-rustic splendor, i.
In the meantime, I hid it in a deep crack in one of the exposed purlins that ran the length of my room.
The roof is of oak, the wall-plates, purlins, and rafters are richly moulded and the tie-beams and principals are richly carved on both sides with various patterns and devices.