BACK a. 3 definitions
e) See under Pressure. -- Back rest, a guide attached to the slide rest of a lathe, and placed in contact with the work, to steady it in turning. -- Back slang, a kind of slang in which every word is written or pronounced backwards; as, nam for man. -- Back stairs, stairs in the back part of a house; private stairs.…
BALL n.
- formerly, the pupil of the eye. -- Ball valve (Mach.), a contrivance by which a ball, placed in a circular cup with a hole in its bottom, operates as a valve. -- Ball vein (Mining), a sort of iron ore, found in loose masses of a globular form, containing sparkling particles. -- Three balls, or Three golden balls,…