to speak in a low, quiet, or indistinct voice, often continuously or to oneself

to mumble to oneself

onomatopoeia for the soft sound of birds chirping, especially swallows

furan (furfuran, used in making nylon) (loanword)

furacilinum (loanword); nitrofurazone

Vietnamese logographic script based on Chinese characters

to whisper in a low voice; to murmur

pyran (chemistry)