- slat (n.)
- late 14c., "a roofing slate," from Old French esclat "split piece, splinter," back-formation from esclater "to break, splinter, burst," probably from Frankish *slaitan "to tear, slit," related to Old High German slizan, Old English slitan (see slit (v.)). Meaning "long, thin, narrow piece of wood or metal" attested from 1764.