Has tasteful associations, but can be shaky in use (5)
I believe the answer is:
cruet
'use' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for cruet that I've seen before include "Set of containers for salt, pepper, oil, vinegar etc" , "Vinegar bottle" , "Small container for seasoning or relish at table" , "Truce over container for table" , "Small container for salt or pepper" .)