"instance of catching sight, action of looking," 1853, verbal noun from sight (v.).
Entries linking to sighting
sight v.
1550s, "look at, view, inspect" (a sense now obsolete), from sight (n.). From c. 1600 as "get sight of, bring into one's view;" 1842 as "take aim along the sight of a firearm." Related: Sighted; sighting.