IPA: /nɒn.dɪˈdɛk.tɪ.bəl/
KK: /nɑnˈdɪk.tə.bəl/
This term describes expenses that cannot be subtracted from taxable income when calculating taxes.
The new tax law made many business expenses nondeductible, increasing the overall tax burden for companies.
Nondeductible → It is formed from "non-" (meaning not) and "deductible" (from Latin "deducere", meaning to lead away or subtract). The word "nondeductible" means not able to be subtracted or not eligible for deduction.
Think of 'not' ('non-') being applied to something that can be 'subtracted' ('deducere') — that's why nondeductible means it cannot be subtracted.