Fishier is an adjective that can be used to describe something suspicious, questionable, or dubious. When searching for synonyms, several options come to mind. One alternative is "shadier", which implies a sense of surreptitiousness or secrecy. Another possibility is "dodgier", suggesting a higher level of potential deceit or dishonesty. "Questionable" is another suitable synonym, indicating doubt or uncertainty surrounding a situation or individual. Additionally, "suspicious" can be used interchangeably with fishier, conveying a sense of mistrust or unease. Lastly, "untrustworthy" captures the essence of fishier, implying a lack of reliability or credibility. These synonyms provide various nuances to accurately describe anything fishy or dubious.