lethargic
/lɪˈθɑːdʒɪk/
adjective
Affected by lethargy; sluggish and apathetic.
Origin
Late Middle English via Latin from Greek lēthargikos, from lēthargos ‘forgetful’.
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After hours of lethargic torpor, George rose from his bed on Sunday afternoon. It only took ten minutes after he'd sat up.