Question

select the appositive or appositive phrase. in 60 ce, the celtic ruler boudica rallied the celts against the romans, organizing an army of twenty thousand while the roman provincial governor of britain was away.

Explanation:

An appositive is a noun or noun - phrase that renames another noun right beside it. In the given sentence, "the Celtic ruler" renames "Boudica".

Answer:

the Celtic ruler