The most common and most likely answer to this crossword clue is the 6 letter word RELICS
R
E
L
I
C
S
More clues leading to the result RELICS
- Odd pieces from Sicilytransported as mementos
- Mementos of priest hoarded by Roman Catholic saint
- Republics with no local souvenirs
- Objects of historical interest found by priest in church seen on the left
- Dereliction showing what's left behind
- Duplicates father removed are mementos
- Developed slicer for leftovers
Buddy explains!

The straight part
We know that "what's left behind" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what's left behind = relics.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 RELICS mean?
RELICS noun- That which remains; that which is left after loss or decay; a remaining portion.
- Something old and outdated, possibly kept for sentimental reasons.
- A part of the body of a saint, or an ancient religious object, kept for veneration.
- (often of guitars) To cause (an object) to appear old or worn, to distress.