As pertaining to an event, item, circumstance or condition, whose outcome or result is less than favourable. Often used as an exclamation of remorse or despair.
Can alternately be used to give a polar definition, when preceded by - the.
Finally, by further addition of the suffix - est, the meaning can be reverted to the original.
The word can be written both combined - megaswan, or as separate words – mega swan. In both cases the pronunciation is the same. Unusual double capitalisation is also common in the written form – Mega Swan.
The word is thought to originate from the Hampshire area of the UK and is supposedly used as a commonplace exclamation in the fireworks industry (uncited).
For example: "That film was megaswan" "I can’t find my car keys. Megaswan!" "There's no cure? Megaswan!"
Alternately, when phrased as a positive: "Man, that party was THE megaswan!" "I love castles, they're THE megaswan." “Bring out THE megaswan!”
And finally: "That was the megaswanest magic act I’ve ever seen”