Memento

n.joyful, thoughtfulwarm

What it means

An object kept because it recalls a person, place, or valued experience.

Reach for it when naming a memory-bearing object whose personal association matters more than its market value

He saved the worn map as a memento of their first mountain crossing.

everyday
reminder
anything prompts recollection or action
not when A reminder can be a message or alarm with no sentimental value.
everyday
souvenir
an item recalls travel, a place, or an event
not when Souvenir often means a purchased product and may lack deep personal meaning.
warm
keepsake
affection gives a small object personal value
not when Keepsake is usually intimate, while a memento may commemorate a public event.
professional
memorabilia
a group of collectible objects is linked to a person or event
not when Memorabilia is usually plural in sense and may be collected for value rather than affection.
formal
token
a small object represents affection, gratitude, or remembrance
not when Token emphasizes symbolic exchange rather than a memory retained by its owner.
literary
relic
an old surviving object carries historical or sacred association
not when Relic stresses age and survival, not a particular owner's memory.

small memento
A small memento from each tour hangs beside the conductor's desk.
keep as a memento
She chose to keep the ribbon as a memento of the opening night.
personal memento
The public archive returned every personal memento to the family.

The definition and the example on this page are written here. The dictionaries above ground which meaning is being described, not the wording.