LCM = Liquid Crystal Module or Liquid Crystal Display Module
Liquid Crystal Module (LCM) and Liquid Crystal Display (LCD) are often used interchangeably. To be pedantic, LCD is the actual glass display, while LCM describes the complete assembly (or module) including printed circuit board (PCB), electronics and back-light. The most used term is LCD or Liquid Crystal Display
References:
http://www.computronics.com.au/ampire/glossary/