The most common and most likely answer to this crossword clue is the 8 letter word ELEVENTY
E
L
E
V
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N
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Y
Buddy explains!
The straight part
We know that "Bilbo’s Magnificent Birthday/Run that invokes the Lord above?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case bilbo’s magnificent birthday/run that invokes the lord above? = eleventy.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 ELEVENTY mean?
ELEVENTY numeral- The number 110, 11 × 10.
- An indefinite large number.