What does the cryptic crossword clue "Trojan's raging lust around foreign king (7)" mean?

The wordplay uses an anagram. anagram of LUST (synonym="LUST") + ROI (synonym="ROI") = TROILUS The answer is TROILUS.

Trojan's raging lust around foreign king (7)

Guardian Cryptic #26527 | 19 Down | 2015-03-24 flower