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STUDY DESIGN A systematic search and review OBJECTIVE.: To investigate the term, degenerative disc disease, to elucidate its current usage and inform clinical, research, and policy recommendations. SUMMARY OF BACKGROUND DATA Degenerative disc disease has long been a dominant concept in common, painful spinal disorders. Yet, despite its pervasiveness and important clinical consequences and controversies, there has not been a systematic examination of its use and meaning in the scientific literature. METHODS We conducted a systematic search of publications using the term degenerative disc disease from 2007 through 2017 in Ovid MEDLINE (R), Embase, CINAHL and Scopus. Two investigators independently reviewed all publications in the primary sample. Publication and author identifiers, and qualitative study descriptors were extracted. Finally, the definition of degenerative disc disease was placed in one of eight categories. Data were summarized using descriptive statistics. RESULTS Degenerative disc disease appeared in the titles of 402 publications in the primary sample and increased in frequency by 189% from the first to the last three years of the decade. No single definition was used in the majority of publications, and most frequently the term was used without any definition provided (30.1%). In other cases, degenerative disc disease specifically included radiculopathy or myelopathy (14.4%), or only back or neck pain (5.5%), or was equated with disc degeneration regardless of the presence of symptoms (15.4%), or with discogenic pain or disc degeneration as a presumed cause of axial pain (12.7%). Another 7.2% comprised a mix of broad ranging findings and diagnoses. The most notable differences in definitions occurred between surgeons and other disciplines, and when applied to cervical vs. lumbar regions. CONCLUSIONS Despite longstanding use and important consequences, degenerative disc disease represents an underdeveloped concept, with greatly varying, disparate definitions documented. Such inconsistencies challenge clear, accurate communication in medicine and science, create confusion and misconceptions among clinicians, patients and others, and hinder the advancement of related knowledge. LEVEL OF EVIDENCE 4.