“steam / to steam” in Japanese is 蒸, read jou, mu (じょう, む). It is a Grade 6 Kyōiku kanji, taught in year 6 of Japanese elementary school, and appears in words such as 蒸気 (steam).
What does 蒸 mean?
お湯が蒸発する。
Same sound, different character — the classic trap. Compare them side by side: