vacile

n. hesitation, hesitating; teasing, pestering

v. vacillate, sway to and fro, fluctuate; hesitate, waver

v. vacillate, hesitate; waver

= shake, waver, falter, vacillate, hang back, oscillate, baulk [balk, -USA], wobble.
Ex: This attitude had to go and by the 1830s it was shaking.
Ex: The first decision in establishing headings for the works of corporate bodies is the one over which code makers have wavered.
Ex: The project faltered because the data became increasingly difficult to input and manipulate.
Ex: Australia's treatment of information technology has vacillated between laissez faire and an interventionist strategy.
Ex: This article explores the implications of these threats, maintaining that publishers cannot afford to hang back, but must innovate or atrophy.
Ex: This dichotomy in Muslim history, which has oscillated between periods of piousness & decadence, demonstrates further disunity in the Muslim world.
Ex: While many scholars concede that military interventions are sometimes permissible, they balk when it comes to deciding whether they are ever a moral duty.
Ex: This adaptation of David Leavitt's novel wobbles between comedy and melodrama, ultimately fudging the novel's spiky empathy.
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* sin vacilar = unswervingly.
* vacilar entre... y/o... = hover between... and/or....