Case of suitable magnitude for elephant? (5)

I believe the answer is:

trunk

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'case' is the definition.
(I know that trunk is a type of baggage)

I don't understand how the rest of the clue works.

(Other definitions for trunk that I've seen before include "on a jumbo?" , "Main stem of tree" , "Baggage item" , "Elephant's nose" , "Torso - part of an elephant - case" .)

I've seen this clue in The Irish Independent.

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