How do you say Spirit in Japanese?

Answer 1

You may say 'seishin' or 'kokoro,' written:　精神　　心

Answer 2

You may use 'yuurei' to refer to "phantoms," and 'yousei' to refer to "sprites, elves, fairies, etc."　They are written (in the same order as mentioned here):　幽霊　妖精

Answer 3

You may say 'seishin' or 'kokoro,' written:　精神　心　If you're referring to "spirit" in the context of something like a ghost, you could say 'yuurei,' written:　幽霊