Fatted calf is a metaphor or symbol of festive celebration and rejoicing for someone's long-awaited return. It derives from the
Parable of the Prodigal Son
The Parable of the Prodigal Son (also known as the parable of the Two Brothers, Lost Son, Loving Father, or of the Forgiving Father; ) is one of the parables of Jesus in the Bible, appearing in Luke 15:11–32. In Luke 15, Jesus tells this sto ...
in the
New Testament
The New Testament (NT) is the second division of the Christian biblical canon. It discusses the teachings and person of Jesus in Christianity, Jesus, as well as events relating to Christianity in the 1st century, first-century Christianit ...
. In biblical times, people would often keep at least one piece of livestock that was fed a special diet to fatten it up, thus making it more flavorsome when prepared as a meal. Slaughtering this livestock was to be done on rare and special occasions. Thus when the prodigal son returns, the father "kills the fatted calf" to show that the celebration is out of the ordinary.
In modern usage, "killing the fatted calf" can simply mean to celebrate in an exuberant manner.
References
The New Dictionary of Cultural Literacy (3rd ed. 2002)
English-language idioms
Biblical phrases
Metaphors referring to food and drink
Metaphors referring to cattle
Parties
Cattle in religion
Animals in the Bible
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