referencia, f., reference; por referencias, by hearsay, indirectly.
referir (ie), to relate, tell.
reflector, m., reflector.
reflejar, to reflect.
reflejo, m., reflection.
reflexionar, to consider, reflect.
refrenar, to check.
refrescar, to refresh.
refugiarse, to take refuge.
refunfuñar (de), to grumble (at), snarl (at).