Cryptic crossword clue
A concert I left early? On the contrary, taking in more unusual mass together 11

The most common and most likely answer to this crossword clue is the 11 letter word AGGLOMERATE

I've seen this crossword clue in Independent
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Buddy explains!

The straight part
We know that "mass together" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case mass together = agglomerate.
The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.
This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.

What does AGGLOMERATE mean?

AGGLOMERATE noun
  1. A collection or mass.
  2. A mass of angular volcanic fragments united by heat; distinguished from conglomerate.
  3. An ice cover of floe formed by the freezing together of various forms of ice.
AGGLOMERATE verb
  1. To wind or collect into a ball; hence, to gather into a mass or anything like a mass.
AGGLOMERATE adjective
  1. Collected into a ball, heap, or mass

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