jet d'eau

from The Century Dictionary.

• noun A fine stream of water spouting from a fountain or pipe, especially an upward jet from an ornamental fountain.

from the GNU version of the Collaborative International Dictionary of English.

• A stream of water spouting, esp. upward, from a fountain or pipe for ornament; also, the fountain or pipe from which it issues.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A stream of water spouting from a fountain or pipe (especially from one arranged to throw water upward), used as an ornament in a garden or public place.