Easton's Bible Dictionary: M. G. Easton, M.A., D.D.
Only in the title of Ps. 5
. It is probably derived from a root meaning "to bore," "perforate," and hence denotes perforated wind instruments of all kinds. The psalm may be thus regarded as addressed to the conductor of the temple choir which played on flutes and such-like instruments.
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.