An acronym is a word made from the initial letters of the words in a particular phrase.
some examples are:
laser - light amplification by the stimulated emission of radiation.
radar - radio aid to detection and ranging.
sac - strategic air command.
mirv - multiple independent reentry vehicle; or multiple impact rocket volley
sam - surface to air missile
NASA - National Aeronautics and Space Administration.
BBW - Big Beautiful Woman; Build a Bear Workshop.