Article Nº 3649 Word, term or place-name Vol. III · p. 650
Traste
Explains 'traste', an old word for the earth or masonry wall lining a levada, now called 'mainel' in Madeira. The term appears in a royal letter of 1493 and has apparently been forgotten in mainland Portugal.
The wall of earth or of stone and mortar that lines the levadas (irrigation channels), known today in Madeira also by the name of levada wall (mainel). The letter of King John II of 8 May 1493 refers to ‘terradas & trastes das levadas’, which shows that the term traste (earth or masonry wall lining a levada), in the sense of mainel, was once used in Portugal, where it now seems to be forgotten.