What does the cryptic crossword clue "Pulse to feel: gal dizzy (9)" mean?

The definition is "Pulse". The wordplay uses an anagram. anagram of TO + FEEL: + GAL = FLAGEOLET; definition: "Pulse" The answer is Flageolet.

Pulse to feel: gal dizzy (9)

Telegraph Prize Cryptic #3001 | 27 Across | 2019-04-28 flower