1598, William Cecil, letter to his son, reprinted in Annals of the reformation and establishment of religion, 1824, by John Strype, page 479,
Trust not any with thy life, credit, or estate: for it is mere folly for a man to entrail himself to his friend; as though, occasion being offered, he shall not dare to become his enemy.
(heraldry) To outline in black.
A cross entrailed.
noun
(usually used in the plural) singular of entrails; an internal organ of an animal.