A short-lived feeling of lethargy or grogginess and sluggishness immediately after awakening from a sleep period. The period that is typically associated with "waking up" and "getting going"
Ministry of Development, Industry and Foreign Trade, Definitions and Abbreviations, GHS (Globally Harmonized System of Classification and Labelling of Chemicals) Brazil, http://www.desenvolvimento.gov.br/arquivos/dwnl_11 97483901.pdf, (Globally Harmonized Sys of Class and Labl of Chem - Brit) {634}