Boyd’s Bible Dictionary:
Singular of Neginoth
(Psa. 61, title).
Concise Bible Dictionary:
A word occurring in the heading of Psalm 4; Psalm 6; Psalm 54; Psalm 55; Psalm 61; Psalm 67; Psalm 76. It is supposed to signify in the plural “on stringed instruments,” as it is translated in Habakkuk 3:19. Neginah, the singular, occurs only in Psalm 61.
Jackson’s Dictionary of Scripture Proper Names:
a harp-song