This noun (neuter plural) denotes the organs or faculties of sense-perception, extended metaphorically to moral and spiritual discernment. Classical usage referred to the five senses and their organs. The author of Hebrews uses it in Hebrews 5:14 describing mature believers who "have their senses trained to discern good and evil." The term emphasizes the faculties of perception—not just intellectual knowledge but the cultivated sensitivities that can detect moral and spiritual realities. Like physical senses that develop through use, these spiritual faculties grow through practice and habit, enabling believers to discern between truth and error, good and evil.