dove's dung

Concise Bible Dictionary:

Some take this in 2 Kings 6:2525And there was a great famine in Samaria: and, behold, they besieged it, until an ass's head was sold for fourscore pieces of silver, and the fourth part of a cab of dove's dung for five pieces of silver. (2 Kings 6:25) to represent a kind of herb; we have plants similarly named, as cowslip, hart’s-tongue, and the Arabs have a herb they call “sparrows’ dung.”

Strong’s Dictionary of Hebrew Words:

Transliteration:
dibyown
Phonic:
dib-yone’
Meaning:
in the margin for the textual reading, cheryown {kher-yone'}; both (in the plural only and) of uncertain derivation; probably some cheap vegetable, perhaps a bulbous root
KJV Usage:
dove's dung