Ukrainian musicians called bandurists played an instrument (which resembles a large fat-bodied guitar).
Explanation:
In the above sentence, the adjective clause is which resembles a large fat-bodied guitar.
Adjective clause are dependent clauses. They modify a noun or a pronoun like the way an adjective does.
These clauses start with words such as which, where, that, those, who, why,what etc. Adjective clauses cannot stand alone as a separate sentence.
They are divided into essential and non essential adjective clauses.
Example of adjective clause is: The school at the right side of the road which is white in colour , is the middle school for this area.
In this sentence the adjective clause is the one which is underlined in the above sentence.