Na·pi·er's bones 
(nāpē-ərz, nə-pîrz)
(nāpē-ərz, nə-pîrz)pl.n. (used with a sing. verb)
A set of graduated rods used to perform multiplication quickly.
[After John Napier.]
- turn one's hand
- turn (one's) head
- turn one's head
- turn out
- turnout
- turn over
- turnover
- turn over a new leaf
- turnpike
- turn signal
- turnsole
- turnspit
- turn state's evidence
- turnstile
- turnstone
- turntable
- turntablism
- turntablist
- turn tail
- turn the/a corner
- turn the corner
- turn the other cheek
- turn the scales
- turn the tables
- turn the trick