What does the cryptic crossword clue "PE gurus could be a bore (7)" mean?

The definition is "bore". The wordplay uses an anagram. anagram of PE + GURUS = UPSURGE; definition: "bore" The answer is UPSURGE.

PE gurus could be a bore (7)

Guardian Cryptic #24389 | 6 Down | 2008-05-15 flower