From the same as lahab with sibilant prefix; a flare of fire -- (flaming) flame.
see HEBREW lahab
H7957. shalhebeth
שַׁלְהֶ֫בֶת noun feminine flame (Aramaic שַׁלְהוֺבִיתָא ) — in שׁ ׳לַהֶבֶת Ezekiel 21:3, of judgment; so שַׁלְהָ֑בֶת Job 15:30; שַׁלְהֶבֶתְיָה אֵשׁ רִשְׁמֵּי Song of Solomon 8:6 i.e. Yahweh-flame = powerful flame (> JägerBAS i.471 JastrJBL xiii (1894), 111 explains יָֿה here as encl. particle)