One of several parallel sloping beams that support a roof WordNet 3.0 & Open English WordNet

A rafter is one of a series of sloped structural members such as steel beams that extend from the ridge or hip to the wall plate, downslope perimeter or eave, and that are designed to support the roof shingles, roof deck, roof covering and its associated loads. Wikipedia

Structural member to support a roof deck. Wikipedia Disambiguation

A rafter which extends from the plate of the roof to the ridge board and to which roofing is attached. OmegaWiki

One of several parallel sloping beams that extend from the ridge to the wall-plate, to support the roof and its associated loads; the sloping top member of a roof truss, which carries the purlins. OmegaWiki

Beam, crossbeam; squared timber; a tie beam of a house, stretching from wall to wall, especially when laid so as to form a loft, "the balks". Wiktionary

Beam. Wiktionary (translation)

One of a series of sloped beams that extend from the ridge or hip to the downslope perimeter or eave, designed to support the roof deck and its associated loads. Wiktionary

One of a series of sloped beams. Wiktionary (translation)