Where does “light-tight” come from?

light-tight (English) comes from English Light, from Middle English light, from Old English lēoht, from Proto-West Germanic leuht, from Proto-Germanic leuhtą, from Proto-Indo-European lewktom, from Proto-Indo-European lewk- — bright; to shine; to see.

light-tight (English): Impervious to light; excluding the light...

Definitions

  1. Impervious to light; excluding the light...

Ancestry of “light-tight”, step by step

light-tight traces back through two separate lines of ancestry.

via English Light

StepLanguageWordMeaning
1EnglishLightA place name
2Middle EnglishlightThe radiation which allows for vision by...
3Old Englishlēohtluminous, bright, light, clear, resplendent,...
4Proto-West Germanicleuhtlight, bright; light
5Proto-Germanicleuhtąlight
6Proto-Indo-Europeanlewktom
7Proto-Indo-Europeanlewk-bright; to shine; to see

via English tight

StepLanguageWordMeaning
1EnglishtightFirmly held together; compact; not loose or open;...
2Middle Englishtight
3Old Englishþiht
Every word from Proto-Indo-European lewk-Every word from Proto-Indo-European lewktomEvery word from Proto-Germanic leuhtą
light-tight — Etymology, Origin & Word History | Etymology Explorer