Meaning

noun an instrument of execution consisting of a wooden frame from which a condemned person is executed by hanging

originFrom Middle English galwes, galewes, plural of galwe, galowe, from Old English galga, gealga, from Proto-West Germanic *galgō, from Proto-Germanic *galgô, from Proto-Indo-European *ǵʰalgʰ-, *ǵʰalg- (“long switch, rod, shaft, pole, perch”). The plural construction probably refers to the vertical and horizontal beams. Compare West Frisian galge, Dutch galg, German Galgen, Danish galge, Icelandic…

Etymology from Wiktionary, CC BY-SA 3.0