長(장) is a Chinese character that means "long." It is also one of the 214 radicals in a Chinese dictionary (옥편). Radicals are the character headings that are used to sort the thousands of characters in a Chinese dictionary. Characters under a radical heading use that radical character as part of its composite structure, similar to how words that begin with an "a" would be found under the letter "A" in an English dictionary. A radical character also can be used as part of another character without being the radical for that character, similar to how "a" can be used in words that are not listed under the letter "A" in an English dictionary (e.g. "cat"). The interesting thing about the radical 長(장) is that there are no Chinese characters listed under it, at least not in my Chinese dictionary.
Why are there no characters under the radical 長(장)? Why make it a radical if it does not organize anything, except itself? Why not just put it under another radical, such as 衣(의)? Can't it be made to fit? Were there once characters under 長(장) that just disappeared over time? Also, 長(장) seems like a very nice character, so why does it appear in few other characters? I can find only four functional characters that make use of 長(장), and none of them use it as their radical. Here they are:
帳(장) curtain; screen
張(장) stretch; display; sheet
脹(창) to have a full stomach; to be swollen
漲(창) to fill up