What is the prefix for well?

There isn't a single, universally accepted prefix for "well". The meaning of "well" needs to be considered to determine an appropriate prefix. For example:

* Well-being: "Well" here acts more as an adverb than a root word with a prefix, describing the state of being.

* Well-adjusted: Similar to "well-being", "well" modifies "adjusted".

* Wellspring: This is a compound word, not one with a prefix in the typical sense.

To find a prefix, you would need to specify what aspect of "well" you're referring to.