Reconnaissance is preliminary research or a preliminary survey such as checking out the lay-of-the-land before taking a military action.(noun)
An example of reconnaissance is when the military has a mission to go to an area and survey the enemy positions.
See reconnaissance in Webster's New World College Dictionary
Origin: Fr, earlier reconnoissance: see recognizance
See reconnaissance in American Heritage Dictionary 4
Origin: , from Old French reconoissance, recognition
Origin: , from reconoistre, reconoiss-, to recognize; see recognize.
Learn more about reconnaissance