What does "hackney" mean?

Additional senses

1. 2.A carriage kept for hire; a hack; a hackney coach.
2. 3.A hired drudge; a hireling; a prostitute.
3. 4.Let out for hire; devoted to common use; hence, much used; trite; mean; as, hackney coaches; hackney authors. "Hackney tongue." Roscommon.
4. 5.To devote to common or frequent use, as a horse or carriage; to wear out in common service; to make trite or commonplace; as, a hackneyed metaphor or quotation. Had I lavish of my presence been, So common-hackneyed in the eyes of men. Shak.
5. 6.To carry in a hackney coach. Cowper.