Probably denominative from chaliyl; a flute -- (plural) Nehiloth.
see HEBREW chaliyl
H5155. nechilah
[נְחִילָה] noun feminine meaning unknown; only; plural in phrase אֶלהַֿנְּחִילוֺת Psalm 5:1 (title); most conjecture = נְחִלּוֺת √חלל = חָלִיל flute; see against this BaeEinl. xi, who thinks (compare ᵐ5 ὑπὲρ τῆς Κληρονομούσης = אֶלהַֿנֹּחֶלֶת [compare ᵑ9], Jerome [Aq Symm] pro hereditatibus = אֶלהַֿנְּחָלֹת) possibly designation of a melody.
II. נָחַל (√ of following; meaning unknown).