IPA: /nɒnˈnjuːklɚ/
KK: /nɑnˈnuklɚ/
Not related to or involving nuclear energy or nuclear weapons.
The country is focusing on nonnuclear energy sources to reduce its carbon footprint.
Nonnuclear is formed from "non-" (meaning not) and "nuclear" (from Latin "nucleus", meaning core or center). The word describes something that is not related to or does not involve nuclear energy or weapons.
Think of 'non-' meaning not, and 'nuclear' referring to the core or center of something. This helps you remember that 'nonnuclear' means something that is not related to the core concept of nuclear energy.