What is a prefix for practical?

There isn't a single, universally accepted prefix for "practical." However, depending on the context, you could use these prefixes:

To emphasize practicality:

* Practo-: This is a less common prefix, but it directly relates to "practical."

* Util-: This prefix implies usefulness and functionality.

* Real-: This suggests groundedness and reality.

* Work-: This indicates action and application.

* App-: This implies applicability and relevance.

Other related prefixes:

* Effic-: This indicates effectiveness and efficiency.

* Use-: This emphasizes the purpose and function.

* Oper-: This suggests operation and working.

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