On The Meaning Of The Word Psalms

The English word “psalms” is a transliteration of the Greek title of the book. That is, this is the Greek word simply spelled in English or Roman letters. The Greek word psalmoi was first translated into Latin as Psalmi, and then into English as “Psalms.” The Greek word originally meant a striking or twitching of the fingers on a string. The related verb was used by classical writers for the “pulling of a bowstring.” From that came the idea of “pulling or playing a stringed musical instrument.” When the word took ons the extended meaning of a song, there was always the latent background of the stringed instrumental accompaniment tied to the singing. So the meaning of the Greek title of the book is “sacred songs sung to musical accompaniment.

 
Ronald B. Allen, And I Will Praise Him: A Guide to Worship in the Psalms, p. 21