http://www.wordnik.com seems to be the best online thesaurus, though one is presented with such a hailstorm of synonyms and near-synonyms and synonyms from divergent disciplines it can be rather overwhelming.
I've used it for several years, but recently found a thesaurus called "Artha" that sits on the desktop and is spectacularly well-designed. It's easy ...
Insults are a tricky part of vernacular to manage since they often vary widely not just by country but by region, the age of the people using them and time period. There's often some overlap but assuming the setting of the story is Earth as we know you'd have to research the specific sort of insults common to the setting.
And err… when the setting is not ...
One place to look is an etymology site. (etymology is word origin): Here is one for "twit". It says, as a noun,
"foolish, stupid and ineffectual person," 1934, British slang, popular 1950s-60s, crossed over to U.S. with British sitcoms. It probably developed from twit (v.) in the sense of "reproach," but it may be influenced by nitwit.
If I am writing a ...
Twit is not unfamiliar to Americans and usually is a childish insult. A Dunce is a person who is incapable of learning (not necessarily because he/she is stupid, as will be discussed in a moment) and is usually used to refer to a child of primary/elementary school age (5-10). The term doesn't ordinarily reflect intelligence, as the term entered into ...
I personally prefer a physical thesaurus for research... there's just a feel to it when crawling through topical sections I have not found online -- searching for a word online is just not the same as trolling through the sections and getting led along.
The 1911 version of Roget's Thesaurus is online and searchable. Being 100+ years old now, it could serve ...
You might do well by digesting relevant English-language media. You can choose the national origin if you want to insult like a particular country's native speaker and you can also somewhat dial in on class, race, time-period etc by the particular films/TV/books you choose.
Your best bet in this scenario will simply be to prevent the reader from forming any false impressions. You can do this by correcting him immediately after the word.
She saw another girl, about fifteen years old.
You can use either girl or woman; be sure to use the word that you would use to describe the viewer.
Have a look at Power Thesaurus - http://www.powerthesaurus.org.
It's very extensive!
The site has simple, easy-to-use layout with low ad-count.
The synonyms are sorted by rating and you can vote as well (and add you own terms as well).
The lists can be filtered by topics (the filters are on the right).
And there are antonyms and other word relations.