onin has many different meanings... but mainly just means that you are welcome to come onin to this site and enjoy the information posted.  

If you are one of the 80,000 or so cross-country joggers around the world known as Hashers, then you already know the various nuances of what onin can mean. It can mean jump onin to a creek, jog onin to a tunnel, or best of all, when you see it written in large letters on the trail it can mean that you have arrived at your goal... that you are about to jog 
onin to a circle of friends. The onin webmaster, Ed German, has been a Hasher since 1989 and is a past Grandmaster of Japan's largest Hash, Samurai Hash House Harriers. Ed is also the founder and a past Grandmaster of Southern Comfort Hash House Harriers in Atlanta. Nowadays, Ed jogs with various Washington, DC area Hashes using an alias name known only to Hashers.