Synonyms for Taxable (same or very similar meaning)
WordNet sense 1 (liable to payment of rates or taxes):
ratable
WordNet sense 2 (subject to import tax):
dutiable
WordNet sense 3 (capable of being assessed especially for the purpose of taxation):
assessable
WordNet sense 4 ((of goods or funds) subject to taxation):
nonexempt
From the ODE community, based on WordNet
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