dissolve
/dɪˈzɒlv/verb
CEFR B1
Definition
To gradually disappear or blend into something else, as if melting away.
Most familiar from chemistry (sugar dissolves in water), but used just as naturally for sound, light, or feelings that fade into their surroundings — a voice dissolving into the evening air, for instance.
Synonyms
melt away
fade away
disperse