IPA: /ɑːrˈtɪk.jʊ.lə.si/
KK: /ɑrˈtɪk.jə.lə.si/
The quality of being able to express thoughts and ideas clearly and effectively.
Her articulacy in discussions made her a great leader.
Articulacy is formed from "articulare" (meaning to utter distinctly) and the suffix "-cy" (indicating a state or quality). The word refers to the quality of being able to express oneself clearly and distinctly.
Think of the ability to 'utter distinctly' ('articulare') as the quality of clear expression, which is what articulacy means.