This is an English medieval surname. It is locational from a former village now called Lashmars Hall in Sussex, itself a place name of great antiquity. The derivation is from the Olde English pre 7th century words 'laecc' meaning a stream, and 'mearc', a boundary. This suggests that the stream formed a parish or hundred boundary. Recorded in several forms including Lashmar, Lashmore, Latchmore, and Lechmere, the surname being locational is largely a "from" name. That is to say a name that was given to a person after he or sometimes she, moved to another place, probably in search of work. The easiest way to identify a stranger being to call that person by the name of the place from whence they came. Spelling being at best erratic and local dialects very thick, lead to the development of variant or "sounds like" spellings of the surname. In this case the first recorded spelling of the family name is believed to be that of William Lechemere. This was dated 1296, in the Pipe Rolls of the county of Sussex, during the reign of King Edward 1st of England, 1272 - 1307. Surnames became necessary when governments introduced personal taxation. In England this was sometimes known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.