Probably from para' and ash; a flea (as the isolated insect) -- flea.
see HEBREW para'
see HEBREW ash
H6550. parosh
I. מַּרְעשׁ noun masculine flea (Assyrian puršu°û, paršu°û; on transposing of, see HomA.u.A.i.21); — figure of insignifance 1 Samuel 24:15; 26:20 ᵐ5 נַפְשִׁי Th We Dr and others