surtax

UK: /ˈsɜː^rtæks/

US: /n., v. ˈsɝˌtæks; v. also sɝˈtæks/

US: (n. sûr′taks′; v. sûr′taks′, sûr taks′)

WordReference Random House Learner's Dictionary of American English © 2026

sur•tax /n., v. ˈsɜrˌtæks; v. also sɜrˈtæks/   n. [countable]

1. an additional tax on something already taxed, esp. a graded tax on incomes.

v. [~ + object]

2. to charge with a surtax.

WordReference Random House Unabridged Dictionary of American English © 2026

sur•tax  (n. sûr′taks′;v. sûr′taks′, sûr taks′), n. 

1. an additional or extra tax on something already taxed.
2. one of a graded series of additional taxes levied on incomes exceeding a certain amount.

v.t. 

3. to put an additional or extra tax on;
   charge with a surtax.

• 1880–85; sur-¹ + tax; compare supertax, French surtaxe

Collins Concise English Dictionary © HarperCollins Publishers::

surtax / ˈsɜːˌtæks/ noun

1. a tax, usually highly progressive, levied on the amount by which a person's income exceeds a specific level
2. an additional tax on something that has already been taxed

verb

1. (transitive) to assess for liability to surtax; charge with an extra tax