Where does “chalkboard” come from?

I notice the chain you've provided contains only English at every step and appears to cycle through "back," "backboard," and "board" repeatedly without reaching an ultimate origin language or a clear etymological path. I cannot write an accurate origin summary because: 1. The chain doesn't show progression to older languages (no Proto-Germanic, Old English, PIE, etc.) 2. It contains circular repetition rather than a linear etymology 3. No original language is specified where the chain actually terminates 4. The meaning of "chalkboard" is marked unknown, so I cannot trace sense development Could you provide the complete etymological chain showing the progression from English back through earlier language stages to the ultimate origin? For example: English chalkboard ← English chalk + English board ← Old English cealk ← Latin calx, etc.

chalkboard (English): A slate or enamel board for writing on with...

Definitions

  1. A slate or enamel board for writing on with...

Ancestry of “chalkboard”, step by step

chalkboard traces back through two separate lines of ancestry.

via English board

StepLanguageWordMeaning
1EnglishboardA relatively long, wide and thin piece of any...
2Englishboardridersurfer
3EnglishriderOne who rides, often on a horse or a motorcycle;...
4Middle EnglishridereAlternative form of ryder
5Middle EnglishryderA rider or equestrian; one who rides a horse; A...
6Old Englishrīdererider, knight
7Old Englishrīdanto ride
8Proto-West Germanicrīdanto ride
9Proto-Germanicrīdanąto ride
10Proto-Indo-Europeanrēydʰ-
11Proto-Indo-Europeanh₂er-to fit, to fix, to put together

via English chalk

StepLanguageWordMeaning
1EnglishchalkA soft, white, powdery limestone; A piece of...
2Middle Englishchalkchalk
3Old Englishcealcplaster, mortar; chalk
4Proto-Germanic*kalk
5Latincalxlimestone; chalk; the finish line
6Ancient Greekχάλιξsmall stone, pebble; gravel, rubble
Every word from Proto-Indo-European h₂er-Every word from Proto-Indo-European rēydʰ-Every word from Proto-Germanic rīdaną