From Longman Dictionary of Contemporary Englishdrain away phrasal verbif something drains away, it is reduced until there is none left I watched the light drain away.anger/confidence/tension/hope etc drains away Sally felt her anger drain away. → drain→ See Verb table
Examples from the Corpus
drain away• Suddenly, palpably, his anger drained away.• I watched the light drain away and felt the cold clawing at the earth between the tables.• We drain away force as we indulge in inner talk.• The waste water would be drained away through a 2,000-foot tunnel, 150 feet below the river level.• There to the west of us, look, the washes all seem to be draining away to the southwest.• Unlike the gentle technique described earlier, anti-cellulite massage should be vigorous to help drain away toxic wastes from the tissues.• It was appalling and ridiculous, and this inner battle was draining away what little strength she had left.• When the spirit flags, the body follows, and Jack Stone was literally draining away with despair and fear. 