Tail-bay

1. (Arch.) One of the joists which rest one end on the wall and the other on a girder; also, the space between a wall and the nearest girder of a floor. Cf. Case-bay.

2. The part of a canal lock below the lower gates.

1. In a framed floor, the space between a wall and the nearest girder of the floor.
2. In a framed floor or roof, a bay, 1 which is next to the end wall; one end of its joists rests on the end wall, the other on a girder.