What does the cryptic crossword clue "Scream as disturbance results in blood bath (8)" mean?

The definition is "blood bath". The wordplay uses an anagram. anagram of SCREAM + AS = MASSACRE; definition: "blood bath" The answer is MASSACRE.

Scream as disturbance results in blood bath (8)

Guardian Cryptic #23907 | 27 Across | 2006-10-26 flower