The most common and most likely answer to this crossword clue is the 11 letter word ENCUMBRANCE
I've seen this crossword clue in The Times
E
N
C
U
M
B
R
A
N
C
E
Buddy explains!
The straight part
We know that "Burden" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case burden = encumbrance.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 ENCUMBRANCE mean?
ENCUMBRANCE noun- Something that encumbers; a burden that must be carried.
- An interest, right, burden, or liability attached to a title of land, such as a lien or mortgage.
- One who is dependent on another.