to change from a liquid to vapor

to disappear gradually

धीरे-धीरे गायब होना

English Usage: His hopes began to evaporate as the deadline approached.

Hindi Usage: जैसे-जैसे समय सीमा नजदीक आती गई, उसकी उम्मीदें धीरे-धीरे गायब होने लगीं।