Celestial shapes lost nonelastic forms (14)

I believe the answer is:

constellations

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'celestial shapes' is the definition.
The answer and definition can be both related to thinking as well as being plural nouns.
Perhaps they are linked in a way I don't understand?

'lost nonelastic forms' is the wordplay.
'forms' is an anagram indicator.
'lost'+'nonelastic'='lostnonelastic'
'lostnonelastic' is an anagram of 'CONSTELLATIONS'.

Can you help me to learn more?

(Another definition for constellations that I've seen is " Groups of stars".)

I've seen this clue in The Daily Express.

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