phrasing - Lingustic term for three consecutive synonyms used in a sentence?

If I recall correctly, in David Brin's "The Uplift War", a species called the Gubru frequently use sentences in which three consecutive synonyms appear to emphasize a topic--presumably a grammatical predisposition on the part of the race. Their language is translated into English (of course) for the reader and might read something like this: "This is terrible, disastrous, dreadful!" (This is an example, not a sentence appearing in the book.) I once stumbled upon an established term that described this triplet usage of consecutive synonyms--and wish I had committed it to paper (or memory). What word might this be?