Capable of being awakened; able to be roused from sleep or a state of inattention.
From 'awake' plus the suffix '-able,' which creates an adjective meaning 'capable of being.' This is a productive English word formation, though not commonly used since 'awake' as an adjective already implies the state.
Some word formations are grammatically perfect but rarely used—'awakable' is one because English speakers just say 'he's a light sleeper' instead of 'he's very awakable'!
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