Nonassertive and Unassertive

Nonassertive adjective - Not aggressively self-assured, though not necessarily lacking in confidence.

Unassertive and nonassertive are semantically related. In some cases you can use "Unassertive" instead an adjective "Nonassertive".

Unassertive adjective - Inclined to timidity or lack of self-confidence.

Nonassertive and unassertive are semantically related. You can use "Nonassertive" instead an adjective "Unassertive".