With each and every Pokémon there seems to be something about them that is based off of one thing or another. For some Pokémon this can be pretty obvious, but others not so much. In the case of Gardevoir it can be somewhat obvious, but I still had to do some research and find out more anyway.
At first glance Gardevoir's physical appearance appears to resemble that of a ballroom dancer. However, its appearance could also be attributed to anesama ningyou––a style of traditional Japanese paper doll––with its exaggerated head with minimal facial expression and an overall frail, featureless physique. Because of its desire to protect its trainer it could also be based off a guardian angel or even a ghost that refuses to leave the world due to their ghost-like characteristics. Whatever the case it is still awesome.
As for the name it is still a little bit of a mystery. From what I've been able to gather though Gardevoir may be a combination of garde (French for guard) and devoir (French for duty). Because of its desire to protect its trainer, and its ability to see into the future, it could also be a combination of garder (French verb for to keep) and voir (French verb for to see). Its Japanese name, Sirknight, could mean saa, naito ("come, knight") or Sir Knight.