From Middle English thakken (“to stroke”), from Old English þaccian (“to touch gently, stroke, tap”), from Proto-Germanic *þakwōną (“to touch lightly”), from Proto-Indo-European *tag-, *taǵ- (“to touch”). Cognate with Old Dutch þakolōn (“to stroke”), Old Norse þykkr (“a thwack, thump, blow”), Icelandic þjökka, þjaka (“to thwack, thump, beat”), Norwegian tjåka (“to strike, beat”), Latin tangō (“touch”). More at thwack, tangent.
thack (plural thacks)
From Middle English thak, thakk, thakke, from Old English þæc, from Proto-Germanic *þaką, from Proto-Indo-European *teg-. Cognate with Dutch dak, Low German Dack, Danish tag (“roof”), German Dach (“roof”), Old Norse þak (“thatch, roof”). Akin to Latin toga (“garment”) and Ancient Greek στέγος (stégos, “roof”). See also thatch.
- the weatherproof outer layer of a roof, often thatch specifically
1952, L.F. Salzman, Building in England, page 223:
- To cover a roof with thack.