Definition of underset in English:
underset
verbundersets, undersettingˈʌndəsɛtˌəndərˈsɛt
[with object]rare Place (something) under something else, especially for support.
〈罕〉置于下方支撑
nounPlural undersetsˈʌndəsɛtˈəndərˌsɛt
another term for undercurrent