What is the synonym for apprehend?

The synonym for "apprehend" depends on the context. Here are some possibilities:

If "apprehend" means to understand:

* Comprehend

* Grasp

* Perceive

* Understand

* Seize (in the sense of mentally grasping)

If "apprehend" means to arrest:

* Capture

* Detain

* Seize

* Take into custody

* Arrest

If "apprehend" means to fear:

* Dread

* Fear

* Be afraid of

* Anticipate with anxiety

The best synonym will depend on the specific meaning of "apprehend" in your context.