What does the cryptic crossword clue "Birds winged, so flying (8)" mean?

The definition is "Birds". The wordplay uses an anagram. anagram of WINGED (synonym="WINGED") + SO (synonym="SO") = WIDGEONS The answer is WIDGEONS.

Birds winged, so flying (8)

Guardian Cryptic #29616 | 24 Across | 2025-02-12 flower