1. pleasant (of a sensation); comfortable; nice
枕、気持ちよさそうだなー。That pillow looks so comfortable.
2. cheerful; happy; feeling good
歌うと気持ちよくなる。Singing puts me in a good mood.
3. smooth (of function); working well
4. agreeable; frank; open; willing
頼んだら気持ちよく手伝ってくれた。When I asked, they gladly helped me.