Lexical Definition

‎χείμαῤῥος‎ cheímarrhos (khi'-mar-hros) brook ^G:N-M
from the base of ‎χειμών‎ and ‎ῥέω‎

brook.

• a storm-runlet, i.e. winter-torrent

Abbott-Smith

χείμμαρος (shortened form of the more usual -οος, Attic contr., -ους), -ον (< χεῖμα, ῥέω) [in LXX chiefly for נַחַל ;]
winter-flowing; as subst., ὁ χ. (sc. ποταμός), a torrent: Jo 18:1.†

Abbott-Smith References

Liddell-Scott-Jones

χείμαρρος, ον,

contraction χειμάρρους, ουν, and shortened χείμαρρος, ον: (χεῖμα, ῥέω):— winter-flowing, swollen by rain and melted snow, of mountain-streams,

__I joined with ποταμός, ὅν τε [the stone] ποταμὸς χείμαρρος ὤσῃ [Refs 8th c.BC+]: frequently in contracted forms, ποταμῷ πλήθοντι ἐοικὼς χειμάρρῳ [Refs 6th c.BC+]
__I.2 πλεκτάνη χείμαρρος seems to be rushing, furious lightning [Refs 4th c.BC+]
__II substantive, torrent, [Refs 5th c.BC+]
__II.2 simply, river, [LXX]
__II.3 drain, gutter, οἱ ἐκ τῶν οἰκιῶν χ. [Refs 4th c.BC+]
__II.4 valley, watercourse, [LXX+2nd c.AD+]

_{LSJ Scripture Refs: LXX.Num.34.5 ☩ LXX.Ps.123.4*}