---

All answers having "Clash" as clue:

3 Character Answers:

---

JAR

WAR



4 Character Answers:

---

DUEL

FEUD

SPAT

TIFF



5 Character Answers:

---

RUNIN

SETTO



6 Character Answers:

---

BATTLE

TUSSLE



7 Character Answers:

---

COLLIDE



8 Character Answers:

---

DISAGREE



9 Character Answers:

---

INTERFERE