There are plenty of synonyms for the phrase "risky businesses", which can be used to describe ventures that are fraught with uncertainty and potential danger. Some of the most common alternatives to "risky businesses" include phrases like "dicey ventures", "tricky propositions", "dangerous undertakings", and "uncertain gambles". Other potential synonyms might include terms like "foolhardy investments", "high-stakes enterprises", "perilous projects", or "risky endeavors". Regardless of which synonym one prefers, all of these phrases reflect the inherent uncertainty and risk involved in pursuing ventures that have the potential to yield great rewards, but are similarly fraught with significant challenges and possible pitfalls.