The most common and most likely answer to this crossword clue is the 10 letter word APOTHEOSIS
I've seen this crossword clue in The Times
A
P
O
T
H
E
O
S
I
S
More clues leading to the result APOTHEOSIS
- A solemn proposal brought about love's consummation
- Ideal example in a Post Office proposition about circular letter
- Glorification of a leading upcoming fellow over old relative
- Crowning point in a reflective work with opinion about love
- Model taking a drug, explosive old girl
- Ideal secretary backed over essay about nothing
- Ace marijuana the man’s absorbing, enormous high
- Apparently, old dissertation contains nothing ideal
- A rejected work proposition includes nothing for great model
- Status Quo covering Prince love the round idolisation
Buddy explains!

The straight part
We know that "consummation" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case consummation = apotheosis.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 APOTHEOSIS mean?
APOTHEOSIS noun- The fact or action of becoming or making into a god; deification.
- Glorification, exaltation; crediting someone or something with extraordinary power or status.
- A glorified example or ideal; the apex or pinnacle (of a concept or belief).
- The best moment or highest point in the development of something, for example of a life or career; the apex, culmination, or climax (of a development).
- Release from earthly life, ascension to heaven; death.
- The latent entity that mediates between a person's psyche and their thoughts. The id, ego and superego in Freudian Psychology are examples of this.