Definitions for "Ule"
A Mexican and Central American tree (Castilloa elastica and Castilloa Markhamiana) related to the breadfruit tree. Its milky juice contains caoutchouc. Called also ule tree.
Ultra-Low Expansion, Corning Glass's successor to Pyrex as a material out of which telescope mirrors are made. U.L.E. expands or contracts very little when the temperature changes, and thus a mirror made out of it holds its shape as the temperature varies without distorting the image.