undercurrent

/AH1 N D ER0 K ER0 AH0 N T/
noun
  1. 1

    A current of water which flows under the surface, and often in a different direction from surface currents.

  2. 2

    A tendency of feeling or opinion that is concealed rather than exposed.

    โ€œThe meeting was pervaded with an undercurrent of dread, as the managers tried not to admit that firings were looming.โ€

verb
  1. 1

    To flow under some surface.

Source: https://en.wiktionary.org/wiki/undercurrent