Noun

(en noun)

a current which flows under the surface

(Totten)

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

* George Eliot

All the while there was a busy undercurrent in her.

:The meeting was pervaded with an undercurrent of dread, as the managers tried not to admit firings were looming.

*{{quote-news

, year=2012 , date=May 9 , author=Jonathan Wilson , title=Europa League: Radamel Falcao's Atlético Madrid rout Athletic Bilbao , work=the Guardian citation , page= , passage=Although the crowd was predominantly red-and-white, there was also a Romanian flavour, which these days in football terms tends to mean there is at least an undercurrent of discontent. }}