IntroductionTo facilitate global implementation of lung cancer (LC) screening and early detection in a quality assured and consistent manner, common terminology is needed. Researchers and clinicians within different specialties may use the same terms but with different meanings or different terms for the same intended meanings. MethodsThe Diagnostics Working Group of the International Association for the Study of Lung Cancer Early Detection and Screening Committee has analyzed and discussed relevant terms used on a regular basis and suggests recommendations for consensus definitions of terminology applicable in this setting. We explored how to reach consensus to define relevant and unambiguous terminology for use by health care providers, researchers, patients, screening participants, and family. ResultsTerms and definitions for epidemiologic and health-economical purposes included the following: standardized incidence and mortality rates, LC-specific survival, long-term survival and cure rates, overdiagnosis, overtreatment, and undertreatment. Terms and definitions for defining screening findings included the following: positive, false-positive, negative, false-negative, and indeterminate findings and additional and incidental findings. Terms and definitions for describing parameters in screening programs included the following: opportunistic versus programmatic screening, screening rounds, interval/interim diagnoses, and invasive and minimally invasive procedures. Terms and definitions for shared decision-making included the following: LC screening—possible harms and risks and LC risk and modifiers prior and posterior to a measure. ConclusionsA common set of terminology with standard definitions is recommended for describing clinical LC screening programs, the discussion about effectiveness and outcomes, or the clinical setting. The use of the terms should be clearly defined and explained.