Where does “sighthole” come from?

sighthole (English) comes from English hole, from Middle English hole, from Old English hol, from Proto-West Germanic hol, from Proto-Germanic hulą, from Proto-Germanic hulaz, from Proto-Indo-European ḱel- — to cover; to incline.

sighthole (English): An eyehole in a furnace, a boiler, etc

Definitions

  1. An eyehole in a furnace, a boiler, etc

Ancestry of “sighthole”, step by step

sighthole traces back through two separate lines of ancestry.

via English hole

StepLanguageWordMeaning
1EnglishholeA hollow place or cavity; an excavation; a pit;...
2Middle Englishholehealthy; safe; whole, complete, full
3Old Englishhola hole, a hollow; calumny; slander
4Proto-West Germanicholhollow; hole
5Proto-Germanichuląa hollow; depression; hole
6Proto-Germanichulazhollow
7Proto-Indo-Europeanḱel-to cover; to incline

via English sight

StepLanguageWordMeaning
1EnglishsightThe ability to see; The act of seeing; perception...
2Middle Englishsightesight
3Middle Englishsiken
4Old Englishsīcanto sigh
5Proto-West Germanic*sīkanto sigh, take a deep breath
Every word from Proto-Indo-European ḱel-Every word from Proto-Germanic hulazEvery word from Proto-Germanic hulą