rigid
- Answer ADAMANT
- Answer FIRM
- Answer HARD
- Answer HARDSET
- Answer HIDEBOUND
- Answer INELASTIC
- Answer IRON
- Answer IRONCLAD
- Answer PRIM
- Answer SET
- Answer STATIC
- Answer STERN
- Answer STIFF
- Answer STONY
- Answer STRICT
- Answer TAUT
- Answer TENSE
- Answer CASTIRON
- Answer STRINGENT