a corner: the angled place where two walls, boards, or sides of a structure meet
This is a builder's word, and it stays one from beginning to end. It marks the angled place where two walls, two boards, or two sides of a structure come together: the rear corners of the tabernacle frame, the four corners of the temple courtyard, the corners of a wooden altar.
In the tabernacle instructions it is close to a technical term. Two extra boards were made for the corners at the back of the structure, doubled from the bottom up and fastened together at the top through a single ring, so the word names a piece of carpentry as much as a location.
In Nehemiah and 2 Chronicles it hardens into a landmark. Jerusalem's wall had a well known bend, and the writers simply call it "the Angle" and assume the reader knows the spot: repair crews work up to it, out from it, and across from it. Nehemiah 3:24 sets it beside a second corner feature, the outer corner (פִּנָּה), so the two were clearly different places along the same wall.
Keeping those two words apart is worth the trouble. The outer corner is the showpiece, the prominent angle of a building that a cornerstone anchors. This word stays with the plain geometry of the joint, and the Bible never stretches it into a picture of anything else.