When it comes to expressing instability or uncertainty, there are a variety of synonyms for the word "shakiest". One alternative is "unsteady", which denotes a lack of firmness or consistency. "Tenuous" is another fitting option, describing something that is fragile or delicate. Additionally, "precarious" reflects a state of uncertainty or insecurity. "Wobbly" is a more informal synonym, conveying the idea of shaky or unbalanced. "Insecure" also serves as a synonym, hinting at a lack of confidence in stability. Lastly, "flimsy" portrays something weak or doubtful, adding to the range of synonyms available to describe the concept of being shakiest.