dead meat n.
1. [mid-19C+] someone who is facing certain death; also in fig. use.
2. [late 19C+] a corpse.
3. [late 19C+] a prostitute, esp. an older woman.
4. [20C+] a horse that has no chance of winning a race; thus dead meat market / shop, a race in which the bulk of contestants are thus characterized.
5. [1900s] (Aus.) in attrib. use of sense 4.
6. [1960s] the flaccid penis.
7. [1980s+] a stupid, dull person.
[1910s+] (Aus./N.Z.) an identity tag.