constructible

Of a land, suitable or allowable for constructing a building on.
Of a building or other thing, capable of being constructed.
That can be constructed in a plane using only a pair of compasses and a straightedge.
Such that the line segment joining it to the origin can be constructed using only a pair of compasses and a straightedge.
Admitting description as a finite union of locally closed (with respect to the Zariski topology) sets.