These words refer to indecisive actions. Hesitate suggests a momentary stopping of activity because of uncertainty, reluctance or a conflict of emotions: She hesitated fearfully between accepting him and denying him; the secretary who hesitates to interrupt her boss when he is in conference. The act of hesitating , of course, may imply a completely mental weighing of alternatives, or an initial immobility before a decision has been made. This contrasts strongly with pause is also the most neutral of all these words in referring to a temporary halt; while all the other words suggest uneasiness, however faintly, pause may suggest a preconceived plan and indicate no irresoluteness whatsoever: They paused for six counts between each pirouette. The point of the word may be brevity: He paused before each painting only long enough to note the painter’s name. Or its point may be to stress the mere fact of the halt, without ascribing motive: uncertain whether she paused at the door out of fear or fascination.

Falter has a much clearer emotional overtone than hesitate or pause . It suggests either intense doubt, helplessness, awkwardness or incompetence: She faltered midway in her denunciation as she saw new reasons to detest him; bushwalkers faltering across the slippery stepping stones; an actor so drunk that he faltered through most of his lines. Falter , like pause , may suggest an interruption, but it can also suggest an extremely slow or faulty performance, as in the last example above. In this sense, flounder is an intensification of falter , referring to a bungled motion that continues erratically because of panic or disablement: obviously unprepared from the way he floundered through the recitation; the sudden cramp that caused him to flounder desperately in the deep water.

Waver and vacillate , by contrast, return to the milder uneasiness of hesitate , although both may suggest a poorly continued motion rather than a temporary halt or initial moment of indecision. Both, in fact, suggest a motion that goes back and forth between two alternatives. Vacillate would be more appropriate to describe mental activity that veers between extremes. Where hesitate in such a context might suggest a suspension of will, vacillate suggests wild swings of choice.

• While she hesitated , he vacillated between taking back his offer and urging her to accept.

Waver would be more appropriate to describe a physical act that reveals uncertainty. In this context, it is close to hesitate ; one who hesitate may not move at all, however, whereas waver suggests slight, indecisive gestures and uneasy movement.

• She hesitated so long that he wavered on his way to join her.

Waver , when it refers to mental activity, suggests less violent swings than vacillate , and between less clearly defined positions: He stood wavering among a thousand dimly imagined possibilities.