---

All answers having "Spiral" as clue:

4 Character Answers:

---

COIL

CURL

GYRE



5 Character Answers:

---

HELIX

LINER

TWIST

WHORL

WITCH



6 Character Answers:

---

GYRATE

NEBULA

WILLOW



7 Character Answers:

---

HELICAL

TORNADO



8 Character Answers:

---

HELICOID



9 Character Answers:

---

CORKSCREW

LETTERBOX



10 Character Answers:

---

HELICOIDAL