| unrelenting(adjective, firmness, hardness, solidity, sturdiness) |
| unswayable(adjective, firmness, hardness, solidity, sturdiness) |
| untractable(adjective, firmness, hardness, solidity, sturdiness) |
| ball field(noun, jewel, rock, mineral, gem) |
| baseball diamond(noun, jewel, rock, mineral, gem) |
| bigoted(adjective, persistence, rigidity, obstinacy, inflexibility) |
| bovine(adjective, persistence, rigidity, obstinacy, inflexibility) |
| brass-bound(adjective, persistence, rigidity, obstinacy, inflexibility) |
| bull-headed(adjective, persistence, rigidity, obstinacy, inflexibility) |
| diamond(noun, jewel, rock, mineral, gem) |
| hard-nosed(adjective, persistence, rigidity, obstinacy, inflexibility) |
| hardheaded(adjective, persistence, rigidity, obstinacy, inflexibility) |
| horny |
| infield(noun, jewel, rock, mineral, gem) |
| mulish(adjective, persistence, rigidity, obstinacy, inflexibility) |
| obstinate(adjective, persistence, rigidity, obstinacy, inflexibility) |
| pertinacious(adjective, persistence, rigidity, obstinacy, inflexibility) |
| pig-headed(adjective, persistence, rigidity, obstinacy, inflexibility) |
| resolute(adjective, persistence, rigidity, obstinacy, inflexibility) |
| rhomb(noun, jewel, rock, mineral, gem) |