Ship of Theseus
Etymology
From a thought experiment recorded by the Greek writer Plutarch: the Athenians preserved Theseus’s ship by replacing its planks one by one, prompting the question of whether it stayed the same ship. The name has clung to the paradox ever since.
noun · /ship uv THEE-see-us/
The puzzle of whether a thing that has had all its parts gradually replaced is still the same thing.
What it names
A handle for identity over time — teams, companies, cities, even yourself, none of whose original parts remain.
Example
New staff, new office, new product — is it the same startup, or a Ship of Theseus that just kept the logo?
Related idea
Where the Ship of Theseus asks about identity, liminal names the in-between of actively becoming something else.