Ancient lights
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
Lights or windows in a house, which have been used in their present state, withbut molestation or interruption, for twenty years, and upwards. To these the owner of the house has a right by prescription or occupancy, so that they cannot be obstructed or closed by the owner of the adjoining land which they may overlook.
Wright v. Freeman, 5 Har. & J. (Md.) 477; Storv v. Odin, 12 Mass. 160, 7 Am. Dec. 8i.