Actually, the word you typed does exist and means something (or else you wouldn't be able to type it on a computer!)
Your conflicting opinion lies here: another character with the insect radical (蟬) means cicada. I have a large piece of jade in the shape of one, and this insect is considered lucky.
But the character you typed is 嬋--it has a woman radical. This can be used to describe women being pretty, beautiful (there are hundreds of such characters). It really shouldn't be used alone, but is found in the following words:
These mean graceful.
The most commonly used word is 嬋娟 (chan-juan).
This character is a phonetic compound, meaning that its pronunciation is based on the way it is written. The base character is 單 which is usually pronounced dan but can also be pronounced chan. And this character originally came from another character (without the two boxes on top) pronounced fan2. So there are many characters now that use 單 as a phonetic element which guides you a bit to the pronunciation. Most Chinese phonetic elements rhyme, and their initial consonants usually occur in the same set of sounds as pronounced in Ancient Chinese, which sometimes has much more variance in Modern Chinese. The following characters use it as a phonetic element:
單 dan1, chan2
癉 dan3, duo4
嘽 tan1, chan3
燀 zhan3, chan3
闡 chan3 灛 chan3
驒 ta2, tuo2, tan2, dian1
鼍 to2, tuo2, tan2
鱓 to2, tuo2, tan2