The Collaborative International Dictionary of English v.0.48:
neginoth \neg"i*noth\, n. pl. [Heb. n[e^]g[imac]n[=o]th.]
Stringed instruments. --Dr. W. Smith.
To the chief musician on Neginoth. --Ps. iv.
Easton's 1897 Bible Dictionary:
i.e., songs with instrumental accompaniment, found in the titles
of Ps. 4; 6; 54; 55; 67; 76; rendered "stringed instruments,"
Hab. 3:19, A.V. It denotes all kinds of stringed instruments, as
the "harp," "psaltery," "viol," etc. The "chief musician on
Neginoth" is the leader of that part of the temple choir which
played on stringed instruments.
Hitchcock's Bible Names Dictionary (late 1800's):
Neginoth, stringed instruments