Brief notes about ten lost souvenirs (8)
I believe the answer is:
mementos
'souvenirs' is the definition.
(I've seen this before)
'brief notes about ten lost' is the wordplay.
'brief notes' becomes 'memos' (memo is a kind of note. I am not sure about the 'brief' bit.**).
'about' indicates putting letters inside.
'lost' is an anagram indicator.
'ten' is an anagram of 'ent'.
'memos' going around 'ent' is 'MEMENTOS'.
Can you help me to learn more?
(Other definitions for mementos that I've seen before include "Tense mom with souvenirs" , "Keepsakes" , "Reminders of past events" .)