The most common and most likely answer to this crossword clue is the 8 letter word LANCELOT
L
A
N
C
E
L
O
T
More clues leading to the result LANCELOT
- Inscribed within church window maybe see knight
- Arthurian knight taking his weapon back to lake
- Legendary knight in a cell, not free
- Legendary knight's weapon, an item for auction
- *He had a weapon against fate
- Knightâs weapon and destiny
- Knight left at once, galloping across line
- Look through window to see legendary adulterer
- Knight provides weapon to many
- Knight from county set with son going to Spain
Buddy explains!

The straight part
We know that "Knight" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case knight = lancelot.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.