Definition of seething in US English:

seething

adjective

  • 1Filled with or characterized by intense but unexpressed anger.

    ‘his seething resentment finally reached boiling point’
  • 2(of a crowd) moving in a rapid or hectic way.

    ‘the seething mass of commuters’

Pronunciation

seething

/ˈsēT͟HiNG//ˈsiðɪŋ/