psal·ter·y 
(sôl
t
ə-r
ē) also
psal·try (sôl
tr
ē)
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.]