§277. Modification

A Phrase is a group of words, without subject or predicate of its own, which may be used as an Adjective or an Adverb.

Thus in the sentence vir fuit summā nōbilitāte, he was a man of the highest nobility, the words summā nōbilitāte, of the highest nobility, are used for the adjective nōbilis, noble (or nōbilissimus, very noble), and are called an Adjective Phrase.

So in the sentence māgnā celeritāte vēnit, he came with great speed, the words māgnā celeritāte, with great speed, are used for the adverb celeriter, quickly (or celerrimē, very quickly), and are called an Adverbial Phrase.