Falstaff loved this bed (4)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Sack is an old name for a kind of fortified wine; Falstaff praises it in the line “If I had a thousand sons, the first humane principle I would teach them should be, to forswear thin potations and to addict themselves to sack.” Sack is also slang for a bed, as in “hit the sack”