IPA: /ˌkɜːrvɪˈlɪnɪərɪti/
KK: /kɜrˌvɪlɪˈnɛrɪti/
The quality or state of having a curved shape or line.
The curvilinearity of the path made it more interesting to walk along.
Curvilinearity is formed from "curvus" (meaning curved) and "linea" (meaning line) combined with the suffix "-ity" (meaning the state or quality of). The term describes the quality or state of being curved in a linear fashion.
Think of 'curved' ('curvus') and 'line' ('linea') to remember that 'curvilinearity' refers to the quality of being curved in a line.
No commonly confused words.