Smoking
noun, verbal noun
If you consume smoke you are smoking.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
喫煙は体に良くないです。
Smoking is not good for you.
この辺りに喫煙室はありますか？
Is there a smoking room in this area?
トーフグの社員には、喫煙する人が一人もいません。
None of Tofugu's employees smoke.