IPA: /nɒnˈpleɪnə/
KK: /nɑnˈpleɪnər/
Not flat or two-dimensional; having parts that are not all in the same plane.
The structure of the molecule is nonplanar, which affects its chemical properties.
Nonplanar → It is formed from "non-" (meaning not) and "planar" (from Latin "planus", meaning flat or level). The word "nonplanar" describes something that is not flat or level, indicating a three-dimensional aspect.
Think of 'non-' meaning 'not' and 'planar' meaning 'flat' — so nonplanar refers to something that is not flat.