libacunculus

Etymology
Diminutive from.

Noun

 * 1)  a type of small cake

Usage notes
This word is a hapax legomenon that occurs only as the ablative singular form libacunculo in Tertullian's De spectaculis (and subsequent sources that quote or reference this passage). Alternative readings are "de lucunculo venenato" (with approximately the same meaning) and "de ranunculo venenato" "from a poisonous frog".