N-COUNT
言下之意；寓意
If something has undertones of a particular kind, it suggests ideas or attitudes of this kind without expressing them directly.
例句
The sobbing voice had an undertone of anger.
啜泣声中隐隐透着愤怒。
...a witty, racy story with surprisingly serious undertones.
诙谐却寓意深刻的荤段子