maybe

https://tts.langeek.co/read?text=bWF5YmU&hash=2e703f0731b07cd2a681f4b1bcf099e778cad535&lang=en&cache-only=0&driver=googletts

probably

https://tts.langeek.co/read?text=cHJvYmFibHk&hash=2f769ea3cd6eb68c2a34c4b3d215f0b2dd97cdd1&lang=en&cache-only=0&driver=googletts

tentatively

https://tts.langeek.co/read?text=dGVudGF0aXZlbHk&hash=4a70892ae9bcf7f1a3b551d141d0faa34a91ef32&lang=en&cache-only=0&driver=googletts

feasibly

https://tts.langeek.co/read?text=ZmVhc2libHk&hash=6250a1183110c6f6f101c727a15b4b9a716d97f6&lang=en&cache-only=0&driver=googletts

perhaps

https://tts.langeek.co/read?text=cGVyaGFwcw&hash=ecf07260b320774d6f3d2373c9d33bac1485b850&lang=en&cache-only=0&driver=googletts

possibly

https://tts.langeek.co/read?text=cG9zc2libHk&hash=d447003ec344ec612b8c0ef449ac021172fa9493&lang=en&cache-only=0&driver=googletts

potentially

https://tts.langeek.co/read?text=cG90ZW50aWFsbHk&hash=10786e64b341880a6d398a0b5cde0a72e8bd3dfb&lang=en&cache-only=0&driver=googletts

(most|very) likely

https://tts.langeek.co/read?text=bW9zdCBsaWtlbHk&hash=68b622a537fdb5a586ee138d735e2c7ed6292f98&lang=en&cache-only=0&driver=googletts

improbably

https://tts.langeek.co/read?text=aW1wcm9iYWJseQ&hash=2d07643a7e142104369bf6e9ce0bfa7ae6cf23f3&lang=en&cache-only=0&driver=googletts

impossibly

https://tts.langeek.co/read?text=aW1wb3NzaWJseQ&hash=df193059a01fd0f104e1c2c8507fdf3e2fdc9286&lang=en&cache-only=0&driver=googletts

reportedly

https://tts.langeek.co/read?text=cmVwb3J0ZWRseQ&hash=dc3041749ecc51be4332b390a3bf48fe0bb524cc&lang=en&cache-only=0&driver=googletts

allegedly

https://tts.langeek.co/read?text=YWxsZWdlZGx5&hash=e373b82cec28d9341b138107bb4944b8ca63cdb1&lang=en&cache-only=0&driver=googletts

purportedly

https://tts.langeek.co/read?text=cHVycG9ydGVkbHk&hash=723307d3c3c360c0ba597ce634ed342de33b9663&lang=en&cache-only=0&driver=googletts

conceivably

https://tts.langeek.co/read?text=Y29uY2VpdmFibHk&hash=fdd8c880ace9ab05739de540ee0f45a80699fc38&lang=en&cache-only=0&driver=googletts

questionably

https://tts.langeek.co/read?text=cXVlc3Rpb25hYmx5&hash=b02d3f9f5ef8b70c29c1e74dfb79e6524776add3&lang=en&cache-only=0&driver=googletts

plausibly

https://tts.langeek.co/read?text=cGxhdXNpYmx5&hash=22b67a17ad69c258d83dfa7a18688031f6168bce&lang=en&cache-only=0&driver=googletts

These adverbs indicate that someone is not sure about their statement or opinion and only consider them possible, like "probably", "perhaps", "allegedly", etc.

Adverbs of Uncertainty

English Adverbs Referring to "Uncertainty"