Fluctuate, v. i. [imp. & p. p. Fluctuated; p. pr. & vb. n. Fluctuating.]
Etymology: [L. fluctuatus, p.p. of fluctuare, to wave, fr. fluctus wave, fr. fluere, fluctum, to flow. See Fluent, and cf. Flotilla.]
1. To move as a wave; to roll hither and thither; to wave; to float backward and forward, as on waves; as, a fluctuating field of air. Blackmore.
2. To move now in one direction and now in another; to be wavering or unsteady; to be irresolute or undetermined; to vacillate.
Syn. -- To waver; vacillate; hesitate; scruple. -- To Fluctuate, Vacillate, Waver. -- Fluctuate is applied both to things and persons and denotes that they move as they are acted upon. The stocks fluctuate; a man fluctuates. between conflicting influences. Vacillate and waver are applied to persons to represent them as acting themselves. A man vacillates when he goes backward and forward in his opinions and purposes, without any fixity of mind or principles. A man wavers when he shrinks back or hesitates at the approach of difficulty or danger. One who is fluctuating in his feelings is usually vacillating in resolve, and wavering in execution.
1 other Webster entry under this spelling
Fluctuate, v. t.
To cause to move as a wave; to put in motion. [R.] And fluctuate all the still perfume. Tennyson.
Shades of meaning
To fluctuate (L. fluctus, a wave) is to move like a wave with alternate rise and fall. A pendulum oscillates; waves fluctuate or undulate; a light or a flame wavers; a frightened steed swerves from his course; a tool or weapon swerves from the mark or line; the temperature varies; the wind veers when it suddenly changes its direction. That which veers may steadily hold the new direction; that which oscillates, fluctuates, undulates, or wavers returns upon its way. As regards mental states, he who hesitates sticks (L. haerere) on the verge of decision; he who wavers does not stick to a decision; he who vacillates decides now one way, and now another; one vacillates between contrasted decisions or actions; he may waver between decision and indecision, or between action and inaction. Persons hesitate, vacillate, waver; feelings fluctuate or vary. Compare shake.