A constructed language invented by noted linguist/science-fiction author Suzette Haden Elgin, intended to be a language specifically by and for women. Elgin contends that most languages out there already, natural and constructed, share a "male" point of view and do not properly reflect a female viewpoint, and women lack words for concepts they really need to talk about.
Agree with the above thesis or don't; the language itself is pretty interesting. It does have its share of words for concepts that are poorly lexicalized in other languages, words that make you blink and realize that they are important and special ideas in their own right after all. It's famous for its rich lexical field of verbs of love ("love for someone sexually desired in the past but not now," "love for someone desired now," "love for someone liked but not respected," "love for someone respected but not liked," "love for the child of one's body," and so on) and some other fields of verbs for emotions (whole series of words for things like "grief with for no reason, with nobody to blame, and nothing to be done about it" and variations on that, to include presence of reason, blame, or remedy, etc).
Some of the premise doesn't hold water to me, but I like the language itself.