Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun undercurrent

2 senses of undercurrent

Sense 1
undertone, undercurrent -- (a subdued emotional quality underlying an utterance; implicit meaning)
       => meaning, substance -- (the idea that is intended; "What is the meaning of this proverb?")

Sense 2
undertide, undercurrent -- (a current below the surface of a fluid)
       => current, stream -- (a steady flow of a fluid (usually from natural causes); "the raft floated downstream on the current"; "he felt a stream of air"; "the hose ejected a stream of water")