1.  diction(n = noun.communication) enunciation - the articulation of speech regarded from the point of view of its intelligibility to the audience;
is a kind of articulation
has particulars: mumbling

2.  diction(n = noun.communication) choice of words, phraseology, phrasing, verbiage, wording - the manner in which something is expressed in words; "use concise military verbiage"
is a kind of expression, formulation
has particulars: mot juste, verbalisation, verbalization

diction, n.
1 the manner of enunciation in speaking or singing.
2 the choice of words or phrases in speech or writing.

Etymology:
F diction or L dictio f. dicere dict- say

N  style, diction, phraseology, wording, manner, strain, composition, mode of expression, choice of words, mode of speech, literary power, ready pen, pen of a ready writer, command of language, authorship, la morgue litteraire, le style c'est de l'homme, style is the dress of thoughts, Various Qualities of Style.