Obi-Wan Kenobi -
Obi is a Japanese sash or belt, used to tie a kimono about the waist. (The word 'obi' in this context commonly appears in crossword puzzles, which is where I learned the meaning of it).
It is customary in Japanese social situations to add the honorific suffix -san to a person's name (as in Hanzo-san), which is equivalent to Mr, Mrs, Master, Miss, etc. -Wan may be a derivative of this honorific suffix. However, the word wan has other meanings in the Japanese language, one of which is the word "one" (Wan and one are phonetically similar too). This probably led to the wild speculation that Obi-Wan Kenobi might have been cloned - hence Obi-Wan(One) Kenobi, a first generation clone. This has since been discounted by the prequel trilogy.
Ken has multiple meanings in Japanese - one of which is sword or saber. So 'Kenobi' literally means 'sword belt.' The weapon of a Jedi, the lightsaber, hangs from his belt, never far from reach.
Japanese names are traditionally written family name (surname) first, then given name last, so Obi-Wan Kenobi could be a westernized homage to that Japanese naming convention. Plus the Jedi's name rolls off the tongue in a more lyrical fashion.