What is a synonym for profound?

Here are some synonyms for "profound", depending on the context:

For depth of thought or feeling:

* Deep

* Intense

* Meaningful

* Significant

* Serious

* Thought-provoking

* Insightful

* Penetrating

* Substantial

* Abysmal

For great depth or extent:

* Immense

* Vast

* Extensive

* Comprehensive

* Unfathomable

For strong impact:

* Powerful

* Moving

* Stirring

* Transformative

* Life-changing

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