The object in question would usually be no longer in use, or perhaps used extremely infrequently compared to when it was first brought. The piece should not be regarded as a waste of space, as the owner would view it with some sort of fondness due the positive experiences associated with its past use, so words like "piece of junk" or "clutter" should be avoided.
Redundant is an adjective (though I would prefer a noun) that might fit this purpose, however it does not reference the fact that the object has been retained out of nostalgia and also has negative connotations rather than positive.
Memento or keepsake are similar words to what I am looking for, however these are kept to remind of a specific person or event and not to remind of the extended past history and actions linked to that specific object itself.
An example might be a toy kept from the past or a laptop stored away after a new one has replaced it. I want to emphasise that in this case, the toy has not been retained because it reminds the owner of their childhood and the laptop has not been conserved because it was given to the owner by someone close to them. They have been kept instead to prompt memories of the interactions that the owner (and usually, only the owner) has had with them.
An example sentence would be something like:
Alice tends to hang onto a lot of _________, such as her PS3 from 10 years ago.
Best Answer
mathom /ˈmæðəm/
A lovely, ancient, and eminently modern word for this is mathom. The OED gives for the current sense of mathom:
But you need to know more about it that just that, for there’s more to it than just that.
Its original sense from Old English is now obsolete:
For its origin OED notes that:
Here’s a Middle English citation:
In other words, “Give us the king and all his gold, and the mathoms of his land.” They were after treasure.
Tolkien’s “playful revival” of the word in a slightly different sense appears first in the Prologue to The Lord of the Rings, where he wrote:
And it has been used by other authors, in non-Hobbitty contexts, since then. For example, the OED provides (among others) a citation from Byte magazine:
See also the LotR Wiki entry for this word, which begins with: