Gobelin stitch is a slanting stitch used in needlepoint

Needlepoint

Needlepoint is a form of counted thread embroidery in which yarn is stitched through a stiff open weave canvas. Most needlepoint designs completely cover the canvas...

. Gobelin stitch takes its name from its resemblance to the texture of woven tapestries produced by the famous French factory at Gobelins

Gobelins manufactory

The Manufacture des Gobelins is a tapestry factory located in Paris, France, at 42 avenue des Gobelins, near the Les Gobelins métro station in the XIIIe arrondissement...

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According to Thérèse de Dilmont in the Encyclopedia of Needlework:

This is worked over two horizontal threads and one perpendicular. In a frame, you can work the second row, from right to left, otherwise, you must turn the work round, and bring out your needle behind the last-made stitch.