The noun meach refers to a fatling — an animal fattened for slaughter, whether for sacrifice or for a feast. Such animals represented the best of the flock or herd and were reserved for special occasions. The word appears in contexts of royal bounty and prophetic pictures of eschatological abundance.
The fatling (meach, mariy, or merie in related forms) represents the best offering — wholehearted generosity to God or honored guests. Saul's failure to destroy the fatlings of Amalek (1 Samuel 15:9) exemplified the principle that partial obedience is disobedience. The eschatological feast of Isaiah 25:6 — 'a feast of rich food, a feast of well-aged wine, of rich food full of marrow' — draws on fatling imagery to picture the messianic banquet. Jesus's Parable of the Prodigal Son echoes this theology: 'bring the fattened calf and kill it, and let us eat and celebrate' (Luke 15:23).