| reflect upon | reflexionar |
| reflectance | reflexion |
| reflected | reflejar |
| reflecting | reflectante |
| reflection | imagen |
| Reflection nebula | Nebulosa de reflexión |
| Reflection symmetry | Eje de simetría |
| Reflections in a Golden Eye | Reflejos de un ojo dorado |
| Reflections on the Revolution in France | Reflexiones sobre la Revolución Francesa |
| reflective | reflexivo |
| reflectometry | reflectometría |
| reflector | reflector |
| Reflector antennas | Antena espejo |
| reflex | reflejo |
| reflexive | reflexivo |
| reflexive pronoun | pronombre reflexivo |
| Reflexive relation | Relación reflexiva |
| Reflexive space | Relación reflexiva |
| reflux | marea baja |
| reforest | repoblar |
| reforestation | repoblación forestal |
| reform | reformar |
| Reform Judaism | Judaísmo reformado |
| reform school | reformatorio |
| Reform Treaty | Tratado de reforma institucional de la Unión Europea |
| Reform War | Guerra de Reforma |
| reformable | corregible |
| reformat | reformatear |
| Reformation | Reforma |
| Reformation Day | Día de la Reforma |
| Reformation Wall | Monumento Internacional de la Reforma |
| reformatory | reformatorio |
| Reformed | reformado |
| Reformed churches | Calvinismo |
| Reformed Churches in the Netherlands | Iglesia Reformada Holandesa |
| reformer | reformador |
| reforming | correctivo |
| Reformist Movement | Movimiento Reformador |
| refract | apartar |
| refracted | baldío |
| refraction | refracción |
| refractive | refractivo |
| Refractive index | Índice de refracción |
| Refractive surgery | Cirugía refractiva |
| refractiveness | resistencia |
| Refractometry | Refractometría |
| refractory | reacio |
| refrain | estribillo |
