To hesitate in purpose or action.
To fail in distinctness or regularity of exercise; said of the mind or of thought.
To cleanse or sift, as barley.
To waver or be unsteady; to weaken or trail off.
To stammer; to utter with hesitation, or in a weak and trembling manner.
To stumble.
To lose faith or vigor; to doubt or abandon (a cause).
An unsteadiness.
To respond in advance
An anticipatory response to expected changes in the environment of a system