wash sale n [probably from the comparison of such a sale to the act of washing, which does not affect the nature of the thing washed]: a sale and purchase of securities that produces no change of the beneficial owner; specif: a sale of securities within 30 days before or after the purchase of substantially identical securities
◇ Any loss from such a sale is not deductible for most taxpayers under the Internal Revenue Code.
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.