Answer:
Subordinate clause: who had barely survived in a war camp
Use: adjective clause.
Explanation:
A clause is a group of words that have a subject and a verb; it can be subordinate (when it does not express a complete thought on its own) or independent (when it expresses a complete thought, and thus, it can stand on its own).
As for adjective clauses, they are subordinate clauses whose function is to modify nouns. We can also identify them because they always follow the noun they modify and they may begin with a relative pronoun (who, whom, whose, that, or which) or a relative adverb (when, where, or why).
In the given sentence, there are two clauses: an independent one: "Roman was an orphan" and a subordinate clause that depends on the latter "who had barely survived in a war camp." Furthermore, the subordinate one is an adjective clause because it describes or modifies the noun "orphan". If any doubt, it also has the other characteristics of an adjective clause: it begins with the relative pronoun "who" and it is next to the noun it modifies.
