[with-hohld, with-] 
verb, -held, -hold⋅ing.| 1. | to hold back; restrain or check. |
| 2. | to refrain from giving or granting: to withhold payment. |
| 3. | to collect (taxes) at the source of income. |
| 4. | to deduct (withholding tax) from an employee's salary or wages. |
| 5. | to hold back; refrain. |
| 6. | to deduct withholding tax. |
| that part of an employee's tax liability withheld by the employer from wages or salary and paid directly to the government. |
| with·hold (wĭth-hōld', wĭth-) v. with·held (-hěld'), with·hold·ing, with·holds v. tr.
To refrain or forbear. [Middle English witholden : with, away from; see with + holden, to hold; see hold1.] with·hold'er n. |
| with·hold·ing (wĭth-hōl'dĭng, wĭth-) n. A portion of an employee's wages or salary withheld by the employer as partial payment of the employee's income tax. Also called withholding tax. |
The tax withheld (or deducted) directly from one's paycheck.
Withholding
Any tax that is taken directly out of an individual's wages or other income before he or she receives the funds.
Investopedia Commentary
In other words, these funds are "withheld" from your wages.
See also: Garnishment, W-4 Form, Withholding Allowance, Withholding Tax
withholding
The holding back of a portion of wages, dividends, interest, pension payments, or various other sources of income for payment of taxes to the U.S. Treasury. See also backup withholding.
The illegal holding back of a portion of securities allocated as part of a new issue to a member of an underwriting syndicate. The underwriter may wish to keep the securities or resell them to a designated party so as to profit from an expected price rise soon after the issue has been offered to the public.