1. 1. Something spent to attain a goal or accomplish a purpose: an expense of time and energy on the project.
   2. A loss for the sake of something gained; a sacrifice: achieved speed at the expense of accuracy.
2. An expenditure of money; a cost: an improvement that was well worth the expense; a trip with all expenses paid.
3. expenses
   1. Charges incurred by an employee in the performance of work: was reimbursed for her travel expenses.
   2. Informal. Money allotted for payment of such charges.
4. Something requiring the expenditure of money: Redecorating the house will be a considerable expense.
5. Archaic. The act of expending.

1. To charge with expenses.
2. To write off as an expense.

at (one's) expense

1. To one's detriment or chagrin: telling jokes at my expense.

[Middle English, from Anglo-Norman, from Latin (pecūnia) expēnsa, (money) paid out, feminine past participle of expendere, to pay out. See expend.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.