overtone

Short definition from Wiktionary

Noun

1. 1
   A tone whose frequency is an integer multiple of another; a member of the harmonic series.
2. 2
   An implicit message (in a film, book, verbal discussion, or similar) perceived as overwhelming the explicit message.
3. 3
   An implicit message (in a film, book, verbal discussion, or similar) perceived subtly alongside, but not overwhelming, the explicit message.

Verb

1. 1
   To give an overtone to.