What is prefix for satisfactory?

There isn't a specific prefix that means "satisfactory". However, there are prefixes that convey similar meanings, depending on the specific nuance you want to express:

For "sufficient" or "adequate":

* Satis-: This is the root of the word "satisfactory" itself, meaning "enough" or "sufficient".

* Suf-: As in "sufficient", meaning "enough".

* Ade-: As in "adequate", meaning "sufficient".

For "pleasing" or "acceptable":

* Bene-: Meaning "good" or "well", as in "beneficial" or "benevolent".

* Satis-: Again, this root can also convey a sense of "pleasing" or "acceptable".

* Grata-: Meaning "pleasing" or "welcome", as in "gratify" or "grateful".

The best prefix to use will depend on the specific context and the precise meaning you want to convey.