Definify.com

Webster 1913 Edition

Adj.

(Arch.)

Having straight joints.

Specifically:

(a)

Applied to a floor the boards of which are so laid that the joints form a continued line transverse to the length of the boards themselves.

Brandle & C.

(b)

In the United States, applied to planking or flooring put together without the tongue and groove, the pieces being laid edge to edge.

straight-joint ‎(not comparable)

(architecture, of a floor) Whose boards are laid so that the joints form a continued line transverse to the length of the boards themselves.
(Can we find and add a quotation of Brande & C to this entry?)
(architecture, US, of flooring or planking) Put together without the tongue and groove, the pieces being laid edge to edge.