yoghurt: [17] It has taken a long time for yoghurt to settle down orthographically, and the process is not yet complete. It was originally acquired (from Turkish yoghurt) in the 1620s as yoghurd, and since then spellings such as yaghourt, yooghort, yughard, yohourth, and yaourt (reflecting the fact that Turkish gh is silent) have been tried. Yoghurt still vies with yogurt. [yoghurt etymology, yoghurt origin, 英语词源]