Etymology From Middle English laththe, laþþe, earlier lathe, laþe, altered from Old English lætt (“lath”), from Proto-West Germanic *lattu, from Proto-Germanic *laþô (compare Dutch lat, German Latte) from Proto-Indo-European *(s)lat- (compare Welsh llath (“rod, wand, yard”)).
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A thin, narrow strip, fastened to the rafters, studs, or floor beams of a building, for the purpose of supporting a covering of tiles, plastering, etc.
It is a piece of wood furnished with two parallel rows of plates, folding over each other, so as to resemble, in some degree, the laths of a blind.1847, editorial staff, “Swimming Skate”, in Scientific American, series 1, Volume 3, Issue 9, page 68:
"You are as thin as a lath and as brown as a nut."1887, Arthur Conan Doyle, A Study in Scarlet:
2 more examples
The rubble waits him, sloping up to broken rear walls in a clogging, an openwork of laths pointlessly chevroning-flooring, furniture, glass, chunks of plaster, long tatters of wallpaper, split and shattered joists […].1973, Thomas Pynchon, Gravity's Rainbow:
Lanna says about wishing she was bigger in the chest and I goes that I had nothing to beat there and I was thin as a lat.1995, Alan Warner, Morvern Callar, Vintage, published 2015, page 21:
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Geography, Geology, Natural sciences, Petrology Microscopic, needle-like crystals, usually of plagioclase feldspar, in a glassy groundmass
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Business, Mining One of the sharp-edged, thick planks driven forward to hold back loose earth or mud when digging the way through for tunnelling or spiling. Also called a spill.
Etymology From Middle English laththe, laþþe, earlier lathe, laþe, altered from Old English lætt (“lath”), from Proto-West Germanic *lattu, from Proto-Germanic *laþô (compare Dutch lat, German Latte) from Proto-Indo-European *(s)lat- (compare Welsh llath (“rod, wand, yard”)).