Abstract Background: Identifying willful brain activity in patients with Disorders of Consciousness (DoC) is critical, as some patients fail to exhibit behavioral signs of consciousness at the bedside but respond to active tasks via neuroimaging or electrophysiological measures. Standardized terminology for this subgroup is absent while it is essential for advancing research and clinical care. To determine the level of consensus among a large group of international experts on terminology and definitions for this clinical entity, as described by terms such as covert awareness (CA), cognitive motor dissociation (CMD), functional locked-in syndrome (fLIS), and non- behavioral minimally conscious state (MCS*). Methods: A Delphi study was conducted using REDCap to evaluate expert agreement on terminology and definitions. The study was conducted among international experts in DoC, primarily from Europe/UK, the USA, and other regions. Findings : Ninety-six experts participated. Among these, 75 (78%) completed both rounds. Participants were predominantly clinical scientists (71%) working in rehabilitation settings (63%). A Delphi method was followed. Consensus on terminology and related definitions was defined as a median score of 5, an interquartile range (IQR) ≤ 1, and ≥ 75% agreement (scores of 4 or 5). Within two rounds, consensus was achieved for over two-thirds of the statements. The term "Covert Awareness" (CA) and its associated definition were identified as the preferred terminology by an international expert panel. Interpretation : We recommend the use of "Covert Awareness" (CA) since our large group of international experts consistently agreed on such preferred term for this subgroup of patients with DoC. This consensus (>75% agreement) establishes a foundation both for future research and clinical standardization. The findings have implications for improving diagnostic accuracy and advancing understanding of covert awareness in DoC, although further study is needed to refine and apply the agreed-upon definition in clinical practice. Funding : Nihil. Research in context Evidence before this study Since the initial description of a patient with covert awareness in 2006 using mental imagery tasks during fMRI, a substantial number of publications has reported similar findings. Two meta-analyses have shown that 14–17% of patients diagnosed behaviorally as being in a vegetative state (VS) actually exhibit willful brain activity detectable through neuroimaging or electrophysiological paradigms. Recent multicenter studies reported that up to 25% of such patients may demonstrate covert command-following. Despite this growing body of evidence, the field has lacked a standardized nomenclature to describe this subgroup of patients. A 2022 systematic review identified 25 different terms in use—such as covert awareness (CA), cognitive motor dissociation (CMD), functional locked-in syndrome (fLIS), and non-behavioral minimally conscious state (MCS*)—underscoring the inconsistency in terminology. No prior study has evaluated expert consensus on preferred terminology and its definition. Added value of this study This study is the first international Delphi consensus effort specifically aimed at determining the most appropriate term and corresponding definition for patients with disorders of consciousness who exhibit willful brain activity detectable only through neuroimaging or electrophysiology. Thanks to a large group of international experts across diverse clinical and research backgrounds, consensus was reached on “Covert Awareness” (CA) as the preferred term, along with a precise definition. This consensus was robust across disciplines and geographic regions. Implications of all the available evidence Establishing consensus on the term “Covert Awareness” (CA) provides a critical foundation for future research, clinical practice, and guideline development. Standardized nomenclature can improve diagnostic consistency, enhance communication across care teams, and promote better public and caregiver understanding. It also enables more rigorous comparative research by providing clear inclusion criteria for future studies. While additional refinement of the definition may be required, this consensus marks a key step in formalizing the recognition of CA as a distinct clinical entity. Future efforts should also consider the development of specialized diagnostic centers and the integration of CA detection into clinical pathways and treatment trials.