noun

• (in the singular) The ability to see.
  "He is losing his sight and now can barely read."
• (often in the plural) Something worth seeing; a spectacle, either good or bad.
  "We went to London and saw all the sights – Buckingham Palace, Tower Bridge, and so on."
• (often in the plural) A device used in aiming a projectile, through which the person aiming looks at the intended target.
• (now colloquial) a great deal, a lot; frequently used to intensify a comparative.
  "a sight of money"

verb

• (transitive) To see; to get sight of (something); to register visually.
  "I was on my way to the door, but all at once, through the fog in my head, I began to sight one reef that I hadn't paid any attention to afore."
• (transitive) To see; to get sight of (something); to register visually.
  "Next a point of known elevation, preferably one of the triangulation stations, is sighted; the vertical angle is read and the horizontal distance is scaled from the point of the setup on the map to the point sighted."
• (transitive) To apply sights to; to adjust the sights of.
  "to sight a rifle or a cannon"
• (transitive, intransitive) To observe or aim (at something) using a (gun) sight.
  "Jim braced the gun and sighted, tried to pull the trigger. Beside him a body collapsed, limp. It was Max. A shot had gone through his brain. Jim stared down at him, numb with horror."