bend sinister
noun
,
Heraldry.
1.
a diagonal band extending from the sinister chief of an escutcheon to the dexter base: a supposed mark of bastardy.
Origin
1615-25
British Dictionary definitions for
bend sinister
bend sinister
noun
1.
(
heraldry
) a diagonal line bisecting a shield from the top right to the bottom left, typically indicating a bastard line