Question

is the group of words in bold a phrase or a clause? usually the result of earthquakes or volcanic activity, tsunamis are enormous ocean waves that can devastate docked ships; meanwhile, ships at sea may not even detect the massive waves. phrase clause

Explanation:

A clause must have a subject and a predicate (a verb - based structure showing action or state). The bolded group "tsunamis are enormous ocean waves" has a subject ("tsunamis") and a predicate ("are enormous ocean waves", where "are" is the verb and "enormous ocean waves" is the subject complement). A phrase lacks a subject - predicate structure. So this is a clause.

Answer:

clause