psal·ter·y 
(sôltə-rē) also psal·try (sôltrē)
(sôltə-rē) also psal·try (sôltrē)n. pl. psal·ter·ies also psal·tries
An ancient stringed instrument played by plucking the strings with the fingers or a plectrum.
[Middle English psalterie, from Old French, from Latin psaltērium, from Greek psaltērion, from psallein, to play the harp; see pāl- in the Appendix of Indo-European roots.]