What's the (still negative) opposite of "arrogant"

Question

The answer is not the word humble nor any derivation thereof. Arrogant being negative epithet has a positive counterpart of humble but I'm looking for the negative opposite, instead.

Arrogant conduct is assuming that ones success is the result of ones excellence and failing to consider that it might be subject to advantageous circumstances.

The opposite of that would be failing to see that any of the progress is due to ones skills nor competence. And that's a negative concept as well.

I can express it by overly humble or excessively timid/self-critical but I want a single word term for precisely that, rather than a description of the property. Insecure won't do because that's a different concept - I'm talking about someone who too often assumes that the success is due to fortunate circumstances.

Answer 1

The term that first came to mind was self-deprecating: tending or serving to disparage or undervalue oneself, but it doesn’t have a negative connotation. You could make it negative by adding “excessively” or “annoyingly”, but without an example of how you want to use the word you’re looking for, it’s difficult to say whether it fits.

Being self-deprecating if you are a celebrity or have a lot of power can be a positive quality. Self-deprecating humor (in general) can be seen as a positive thing unless it is excessive.

Self-effacing: having or showing a tendency to make oneself modestly or shyly inconspicuous, is a related word. I don’t think it fits though because it is more about avoiding attention than being self-critical.

Answer 2

Removing any words I would consider positive from this list of antonyms of arrogant I found on Merriam Webster:

Near Antonyms of arrogant:

cowering, cringing, mousy (or mousey), overmodest, sheepish, shrinking, shy, subdued, timid, meek, submissive, unassertive, yielding

It's hard to pick one without knowing the context in which you are using it.