健康, けんこう
1. health
NA-adjective
2. healthy, sound, fit, wholesome
煙草をすうことは健康に悪い。
が
Particle
1. indicates sentence subject (occasionally object)
2. indicates possessive (esp. in literary expressions)
Conjunction
3. but, however, still, and
after the volitional form of a verb
4. regardless of, whether (or not)