What is a prefix for believeable?

There isn't a single, perfect prefix that makes "believable" more impactful. The best option depends on the nuance you want to convey. Here are some possibilities:

For emphasizing strong belief:

* Un-: "Unbelievable" emphasizes the opposite of being believable.

* Highly: "Highly believable" emphasizes a strong degree of believability.

For emphasizing truthfulness:

* Credible: "Credible" means trustworthy and believable.

* Authentic: "Authentic" means genuine and believable.

For emphasizing persuasiveness:

* Compelling: "Compelling" means persuasive and believable.

* Convincing: "Convincing" emphasizes the power of the evidence to make something believable.

For emphasizing an element of doubt:

* Semi-: "Semi-believable" suggests that something is partially believable.

* Questionable: "Questionable" suggests that the believability is in doubt.

For emphasizing the act of making something believable:

* Make-: "Make-believable" emphasizes the action of making something seem believable.

* Render: "Render believable" emphasizes the act of making something believable through specific means.

The best prefix will depend on the specific context and what you want to emphasize about "believable."