The Collaborative International Dictionary of English v.0.48:
Rack \Rack\ (r[a^]k), v. t.
1. To extend by the application of force; to stretch or
strain; specifically, to stretch on the rack or wheel; to
torture by an engine which strains the limbs and pulls the
He was racked and miserably tormented. --Foxe.
2. To torment; to torture; to affect with extreme pain or
Vaunting aloud but racked with deep despair.
3. To stretch or strain, in a figurative sense; hence, to
harass, or oppress by extortion.
The landlords there shamefully rack their tenants.
They [landlords] rack their rents an ace too high.
Grant that I may never rack a Scripture simile
beyond the true intent thereof. --Fuller.
Try what my credit can in Venice do;
That shall be racked even to the uttermost. --Shak.
4. (Mining) To wash on a rack, as metals or ore.
5. (Naut.) To bind together, as two ropes, with cross turns
of yarn, marline, etc.
To rack one's brains or To rack one's brains out or To
rack one's wits, to exert one's thinking processes to the
utmost for the purpose of accomplishing something; as, I
racked my brains out trying to find a way to solve the
[1913 Webster +PJC]
Syn: To torture; torment; rend; tear.