imponible
taxable
impose
to force upon
+
-ible
able to be
Imponible means taxable and can be thought of as impose0 + -ible1, literally meaning able to be imposed1 (as in taxes being imposed or forced upon someone).
adjective
- taxableSubject to taxation or capable of being taxedLos ingresos imponibles deben declararse en la declaración de impuestos. // Taxable income must be reported on the tax return.