It is believed that the surname Romm derives from the Hebrew Language Acronym Resh Aleph Mem which is short for "Rosh Metivta" - ie: Head of Yeshiva. It is pronounced Romm (and not Re'em, as it would be in modern Hebrew) since the Ashkenazim at the time spoke Yiddish, and therefore put a kamatz under the Aleph, rendering the "oh" sound.