Submissive

this word can be found in a variety of dictionaries you have on the web. I looked it up in google finding...:

dutiful - meek - submissive - docile at the site:

http://www.wordreference.com/es/

There are other related concepts perhaps, given the context we were talking about. Perhaps introverted, timid, having low self-esteem, etc.

I've put some NEW links to the right on vocabulary. The site Visuwords allows you to create maps of words and even save them with an app. Wordle allows you to put in a text (something you're reading for example and check frequency of words in a very visual way. Try them I say!