In the long history of the world only a few generations have been granted the role of defending freedom

In the long history of the world, only a few generations have been granted the role of defending freedom in its hour of maximum danger. ... The energy, the faith, the devotion which we bring to this endeavor will light our country and all who serve it; and the glow from that fire can truly light the world.

Explanation:

John F. Kennedy Inaugural Address (1961)

true. the definition explains it: a word or phrase that modifies or qualifies an adjective, verb, or other adverb or a word group, expressing a relation of place, time, circumstance, manner, cause, degree, etc. this is a dictionary definition that i have looked up in a dictionary.