Mont Blanc is a mountain in the Montes Alpes range. Its width is about 25 kilometers; the height is 3.7–3.8 km above adjacent plains of Mare Imbrium and 1.12 km above lunar level of zero elevation The name , the highest mountain of terrestrial Alps, was proposed for this mountain by Johann Hieronymus Schröter. (wikipedia entry)
A mons is a mountain. On the Moon they are named after terrestrial mountain ranges, nearby craters, and deceased scientists who have made outstanding or fundamental contributions to their fields.