a horizontal architectural member supporting the weight above an opening, as a window or a door.
Also British, lin·tol.
Origin of lintel
1350–1400;Middle Englishlyntel < Middle Frenchlintel, dissimilated variant of *linter < Latinlīmitāris orig., belonging to or indicating a boundary; later taken as synonym of līmināris orig., of the threshold. See limit, -ar1
early 14c., from Old French lintel "threshold" (13c., Modern French linteau), of uncertain origin, probably a variant of lintier, from Vulgar Latin *limitaris "threshold," from Latin limitaris (adj.) "that is on the border," from limes (genitive limitis) "border, boundary" (see limit (n.)). Altered by influence of Latin limen "threshold."