Sentence:  Since his majesty went into the field, I have seen her rise from her bed, throw her nightgown upon her, unlock her closet, take forth paper, fold it, write upon't, read it, afterwards seal it, and again return to bed; yet all this while in a most <WSD>fast</WSD> sleep. 
Meaning of the word marked with <WSD> tags:  Deep or sound (of sleep); fast asleep (of people). (16th-19th c.)