Tailless hornet possibly seen in flight! (5)
I believe the answer is:
heron
'in flight' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'tailless hornet possibly' is the wordplay.
'tailless' means to remove the last letter (the tail of the word is removed).
'possibly' is an anagram indicator.
'hornet' with its final letter removed is 'horne'.
'horne' anagrammed gives 'HERON'.
'seen' is the link.
Can you help me to learn more?
(Other definitions for heron that I've seen before include "Wader" , "One bird" , "Grey or white long-legged wading bird" , "Tall wading bird" , "eg Egret" .)