Someone who is born completely disabled, mentally, and has no potential to develop. Can also refer to someone who is beyond lazy and lifeless.
Babies deceasing in the womb are likely to become Meat Packets, sequentially.

Informally:

Bill: "This mother fucker lived his entire existence in his room...what a meat packet."
by hippigorilla April 26, 2020
Get the Meat Packet mug.