D defs.my
Entry 1 sense Webster, 1913

Formaldehyde

/fôr-măl'-dəh-īdˌ/ · For·mal·de·hyde · IPA /fɔː(ɹ)ˈmældɪhaɪd/
01 n. A colorless, volatile liquid, H2CO, resembling acetic or ethyl aldehyde, and chemically intermediate between methyl alcohol and formic acid.
  1. 1.
    A colorless, volatile liquid, H2CO, resembling acetic or ethyl aldehyde, and chemically intermediate between methyl alcohol and formic acid.(Chem.)