Where does “trainstop” come from?

trainstop (English) comes from English train, from Middle English train, from Old French train, from Old French traïner, from Vulgar Latin traginare, from Latin tragēre, from Latin trahere, from Latin traho — to run.

Ancestry of “trainstop”, step by step

trainstop traces back through two separate lines of ancestry.

via English train

StepLanguageWordMeaning
1EnglishtrainElongated portion; Connected sequence of people...
2Middle Englishtrain
3Old Frenchtraina delay, a drawing out
4Old FrenchtraïnerAlternative form of trainer; to pull out, to draw
5Vulgar Latintraginarepresent active infinitive of *traginō
6Latintragēre
7Latintraheresecond-person singular future passive indicative...
8LatintrahoI drag, pull; I trail; I extract, withdraw
9Proto-Italictraɣō
10Proto-Indo-Europeantregʰ-to drag, pull?; to run, walk
11Proto-Indo-Europeandʰregʰ-to run

via English stop

StepLanguageWordMeaning
1EnglishstopTo cease moving; To not continue; To cause to...
2EnglishtopThe highest or uppermost part of something; A...
3Middle EnglishtopThe summit or top of something, especially a...
4Old Englishtopptop, summit (of something)
5Proto-West Germanic*topptop, summit, crest
6Proto-Germanictuppaztuft, plait; top, summit
7Proto-Indo-Europeandumb-tail, rod, staff, pole, penis; tail, rod, staff,...
Every word from Proto-Indo-European dʰregʰ-Every word from Proto-Indo-European tregʰ-Every word from Proto-Italic traɣō