noun the act of reconnoitering; preliminary examination or survey.
2. reconnaissance ·noun an examination or survey of a region in reference to its general geological character.
3. reconnaissance ·noun an examination of a territory, or of an enemy's position, for the purpose of obtaining information necessary for directing military operations; a preparatory expedition.
4. reconnaissance ·noun an examination of a region as to its general natural features, preparatory to a more particular survey for the purposes of triangulation, or of determining the location of a public work.