IPA: /nɒnˈtæksəbl/
KK: /nɑnˈtæksəbl/
Not subject to taxation or not required to pay taxes.
Certain types of income, like gifts, can be considered nontaxable.
Nontaxable → It is formed from "non-" (meaning not) and "taxable" (from Latin "taxare", meaning to assess or estimate). The word "nontaxable" means not subject to assessment or taxation.
Think of 'non-' meaning not, and 'taxable' meaning subject to tax — so nontaxable means something that is not subject to tax.