רִיבּוּעַ, (רָבַע) a square. Zeb. 62ᵃ קרן … ור׳ מעכבין the horn, the ascent, the foundation, and the square shape are indispensable conditions for the altar. Ib. 108ᵇ; a. fr.—ר׳ עולם the cardinal points of the world. Tosef. Erub. VI (V), 3; Erub. 56Erub. 56ᵃ בא לרבעה מרבעה בר׳ ע׳ וכ׳ when you square a town (for Sabbath limits, v. רָבַע), you must square it in accordance with the cardinal points, and the marks are Charles’s Wain in the north &c. Ib. אם אינו … בר׳ וכ׳ if you do not know how to square it in accordance with the cardinal points &c.; a. e.