The noun follows from the verb. Ultimately from the root י־ר־ד (y-r-d).
יוֹרֶדֶת • (yoréd)
יוֹרֶדֶת • (yorédet) f (plural indefinite יוֹרְדוֹת, singular construct יוֹרֶדֶת־, masculine counterpart יוֹרֵד)