Why is the ninth month called September?
early 14c., hurteln, "to crash together; to crash down, knock down," probably frequentative of hurten (see hurt (v.)) in its original sense. Intransitive meaning "to rush, dash, charge" is late 14c. The essential notion in hurtle is that of forcible collision, in hurl that of forcible projection. Related: Hurtled; hurtling.