the part of the dividend that is left over when the dividend is not evenly divisible by the divisor
"When dividing twelve cookies among five friends, three are distributed to each person while a remainder of two cookies is left over."
the number that remains after subtraction; the number that when added to the subtrahend gives the minuend
"When you subtract four from ten, the remainder is six because adding six back to four returns the original number ten."
A part or parts remaining after some has/have been removed.
"After selling half of her inventory, she packed the remainder into boxes to ship later."
In plain English: A remainder is whatever amount of something is left over after you have taken out as much as needed.
"There were twenty students in class, and three missed school, so seventeen remained to take the test today."
Usage: Use remainder when referring to the specific quantity of something that is left over, such as books marked for a sale because they are unsold. Do not confuse this with "remnant," which implies small scraps rather than a defined leftover amount.
To mark or declare items left unsold as subject to reduction in price.
"The manager decided to remainder all the winter coats at half price before they went out of season."
In plain English: To leave something behind after you have taken what you need is to remainder it, though this specific usage of the word as a verb is very rare and usually people just say they left something over instead.
"The remainder left over from his lunch will be eaten for dinner tonight."
Remaining.
"Only five cookies remained after everyone had taken their share."
The word remainder comes from the Old French verb remaindre, which was borrowed into Middle English and originally meant "to stay behind." It entered modern usage when this action of staying was treated directly as a noun to describe what is left over after something else has been taken away.