IPA: /kəˈpeɪʃəsnəs/
KK: /kəˈpeɪʃəsnəs/
The quality of having a lot of space or being able to hold a lot.
The capaciousness of the new storage room allowed us to keep all our supplies organized.
Capaciousness is formed from "capax" (from Latin, meaning able to hold) and the suffix "-ous" (meaning full of) combined with "-ness" (indicating a state or quality). The word describes the quality of being able to hold a lot or being spacious.
Think of 'capax' meaning able to hold, and remember that 'capaciousness' refers to the quality of being spacious or able to hold much.