Definitions: 1. Abbreviation for functional residual capacity (of lungs). The definition information for FRC is provided by Stedman's. You can search our medical dictionary here.Stedman's, part of Lippincott Williams & Wilkins, provides a comprehensive line of health-science publications for healthcare professionals and medical students.bbreviation for functional residual capacity (of lungs). The definition information for FRC is provided by Stedman's. You can search our medical dictionary here.