to get (a child, invalid, etc.) ready for sleep, as in a bed
to lock (type, plates, etc.) into a form and place on a printing press
to get an edition (of a newspaper, etc.) ready for printing
take to one's bed
to go to bed because of illness, etc.
See bed in American Heritage Dictionary 4 Idioms
get into bed with
To become closely involved with another person or group, as in an intrigue: “The Israelis were experienced at this kind of [covert] … work, but it was essential that the administration not get into bed with them on this”(Bob Woodward).