An Etymological Dictionary of the German Language/Latte
Latte, f., ‘lath,’ from the equiv. MidHG. late, latte, OHG. latta, f.; it corresponds to Du. lat, AS. lœtta (lœþþa?), MidE. laþþe, E. lath; a difficult word both grammatically and etymologically. The correspondence of tt in AS. lœtta and OHG. latta is abnormal (AS. tt ought to be HG. tz, only AS. þþ corresponds to a HG. tt). Unfortunately a corresponding word is wanting both in Scand. and Goth. Yet there is no need to regard the cognates as foreign; since ModHG. Laden is cognate, the Teut. origin of the word is established. Hence from HG. Latte an allied Rom. class has been rightly derived — Fr. latte, Ital. latta, ‘flat wooden pole.’ To the Teut. cognates Ir. slath (Bret. laz), ‘rod, pole,’ from the base slattâ, is primit. akin.