Esprit de corps (not esprit du corps) is French for spirit of body. Body here refers not to the human body but rather to a body of multiple people—for example, a military unit, a business, or a sports team. To have esprit de corps is to have high regard and pride for the body to which one belongs.
The expression has a long history in French, and it has been in English for a long time as well, with the first documented instances appearing in the second half of the 18th century.1 It was and is often misspelled esprit du corps, which is nonsensical in French (du means of the when it precedes a masculine noun, but it becomes de la when it precedes a feminine noun; corps is feminine).
Loan phrases such as this one are italicized when they are new to English. But esprit de corps has been in the language over two centuries, so there’s no need to italicize it in normal use, nor should it be capitalized or placed in quotation marks.
He was impressed by the rising-tide-floats-all-ships camaraderie and esprit de corps of those gathered at the annual Crafter Brewers Conference in San Diego. [San Antonio Current]
Units will also lead esprit de corps events for additional team building and to balance out the weight of the issues discussed. [Clarkville Leaf Chronicle]
So strong was the bond than it appeared their cause reflected not simply an esprit de corps but a deep Iberian pride. [Telegraph]
Like most of Silicon Valley’s hot companies, Facebook doles out equity to employees. In theory, this helps to create an esprit de corps and align the interests of workers, managers and investors. [Globe and Mail]
They have used coaches from outside the area and while that raised some of the skills, some of the esprit de corps lapsed. [New Zealand Herald]