| Principal Translations |
WordReference English-Spanish Dictionary © 2026:
| fastness n | (state of being secure) | fortaleza nf |
| | | refugio nm |
| | The fastness of the politician's ideals make him an excellent candidate for the party. |
| fastness n | (permanence) | firmeza nf |
| | | adherencia nf |
| | | permanencia nf |
| | The researcher developed a new process to test the fastness of various adhesives. |
| fastness n | (dye: permanence) | permanencia nf |
| | | inalterabilidad nf |
| Note: Often used as a suffix: colour fastness, lightfastness |
| | The company is testing a new additive to improve the fastness of their dyes. |
| | La compañía está probando un nuevo aditivo para mejorar la permanencia de sus tinturas. |