---

All answers having "Undulating" as clue:

3 Character Answers:

---

TOW



4 Character Answers:

---

WAVY



5 Character Answers:

---

AGENT

CURLY

HAVOC

HILLY



6 Character Answers:

---

WIGGLY



7 Character Answers:

---

SINUOUS



8 Character Answers:

---

YEARLING