As tough as old boots and Hard-bitten

Hard-bitten and as tough as old boots are semantically related In some cases you can replace phrase "Hard-bitten" with "As tough as old boots", this phrases are similar.

Hard-bitten adjective - Able to withstand hardship, strain, or exposure.

As tough as old boots and hard-bitten are semantically related in hard-nosed topic. You can use "As tough as old boots" instead an adjective phrase "Hard-bitten". informal substitute