Gerlach is a male forename of Germanic origin, variations of which exist in many Germanic and Romance languages. Like many other early Germanic names, it is dithematic, consisting of two meaningful constituents put together. In this case, those constituents are ger (meaning 'spear') and /la:k / (meaning 'motion'). The meaning of the name is thus 'spear thrower'. It became a surname, and a source from which other surnames have been derived, as well.
