undulation

/AH1 N JH AH0 L EY1 SH AH0 N/
noun
  1. 1

    An instance or act of undulating.

  2. 2

    A wavy appearance or outline; waviness.

  3. 3

    A tremulous tone produced by a peculiar pressure of the finger on a string.

  4. 4

    A wavelike curve; a smooth and regular rise and fall.

  5. 5

    A wavelike motion of the air; electromagnetic radiation.

  6. 6

    A feeling as if of an undulatory motion about the heart.

  7. 7

    The distinctive motion of the matter within an abscess on being pressed when it is ripe for opening.

Source: https://en.wiktionary.org/wiki/undulation