Home › Words › T › trolandtrolandtroland means A unit (symbol Td) of conventional retinal illuminance, intended as a means of correcting photometric measurements of luminance values impinging on the human eye by scaling them by the effective pupil size.Among words judged in Lexicurio's Arena, troland ranks #35,726 of 42,789 for Qualifying.EtymologyNamed after Leonard T. Troland.nounA unit (symbol Td) of conventional retinal illuminance, intended as a means of correcting photometric measurements of luminance values impinging on the human eye by scaling them by the effective pupil size.Definitions & examples from Wiktionary (CC BY-SA 3.0).