What does the cryptic crossword clue "Incendiary mob with brief frenzy (8)" mean?

The definition is "Incendiary". The wordplay uses an anagram. anagram of MOB + BRIEF = FIREBOMB; definition: "Incendiary" The answer is FIREBOMB.

Incendiary mob with brief frenzy (8)

Guardian Cryptic #22974 | 15 Down | 2003-10-29 flower