Falseheart

Sometimes, because of the invasion of germs into the heart part, the brown or tawny falseheart with irregular figure appears.

Source: wiktionary

Fungi break down the wood inwards from lopping wounds, causing white or brown rot. It occurs faster in old wood and wood no longer needed by the tree (depending on species and whether heartwood or falseheart is present).

Source: wiktionary

I know her thoroughly; I have studied her thoroughly; I have looked into her falseheart. Nobody has discovered her but me.

Source: wiktionary

Slay the craven falsehearts, who speak lies for truth to give the dishonest measure of a false balance for the even, well-pressed measure of clearness, cleanness and righteousness.

Source: wiktionary