reviendront

/ʁəvjɛ̃dʁɔ̃/revenir
1.
verbInd3rdFutPlur3

will come back

will return

T'inquiète, ils reviendront bientôt.

Don't worry, they will come back soon.

2.
verbInd3rdFutPlur3

will cost (colloquial)

Finalement, les travaux nous reviendront chers.

In the end, the renovations will cost us a lot.