What does «fluctuar» mean in Spanish?

To cast a body over the waters.
To ripple, to be carried by the waves.

Examples of use in Spanish: "la barca fluctúa".
To oscillate; to grow and shrink alternately.

Examples of use in Spanish: "fluctuar los valores en Bolsa".
To hesitate, to doubt.

Examples of use in Spanish: "fluctuar en la resolución de algo".