1) Ailing or sleeping 2) All set for slumbering 3) All tucked in 4) All tucked in for the night 5) Already retired 6) Asleep 7) Beneath the covers 8) Between the sheets 9) Bunked 10) Confined to bed 11) Down for the night 12) Dreaming 13) Emulating a sleepyhead 14) Exclusively Saxon word 15) Exclusively Anglo word 
• (adv.) In bed, or on the bed. • (adv.) To childbed (in the phrase `brought abed,` that is, delivered of a child).
A·bed' adverb [ Prefix a- in, on + bed .] 1. In bed, or on the bed. « Not to be abed after midnight. Shak. » 2. To childbed (in the phrase ' brought abed ,' that is, delivered of a child). Shak. 
[adv] - in bed
adverb in bed
in bed: to stay abed late on Sundays. · confined to bed.