Sex-repulsed is a term that is used most commonly by asexual and other ace-spec individuals to indicate that they find sexual activity undesirable (perhaps repulsive/disgusting/revolting), uninteresting, or otherwise uncomfortable or unwanted. Sex-repulsion can take many different forms. Some are repulsed by the idea of engaging in sex themselves, but are fine with sexual activity that does not involve them. These people may identify as sex-averse. Other people may be repulsed by the idea of sex in general. For some people, sex-repulsion is only directed at the act of intercourse; for other people, repulsion may extend to other sexual acts. Some people may experience varying amounts of sex-repulsion.
Some people use sex-aversion and sex-repulsion interchangably, but to many these are distinct experiences. Sex-aversion specifically refers to negative feelings regarding the idea of oneself being in a sexual situation. Aversion to the idea of sex in general would fall under sex-repulsion. Repulsion also has the association of stronger negative feelings like fear or disgust, or physical reactions like cringing, shaking, pain, or nausea. These can still be present in sex-aversion, but only in relation to one's own participation in sexual activity.
It is important to note that being sex-repulsed is not the same as being sex negative. "Sex negativity", also called antisexualism, is a term that is often used by those who are hostile towards sexual behavior or sexuality. It is also often used by SWERFs and/or those against sex workers or the creation of sexual media (such as pornography.) People strongly repulsed by the general idea of sex can still be supportive of others' sexual freedoms.
Sex-repusion isn't essentially related to sexophobia, genophobia, haphephobia, anthrophobia, misanthropy, social phobia, philemaphobia/philematophobia, philophobia or erotophobia.
Not all asexuals are sex-repulsed; many are averse, indifferent or ambivalent about sex, or may be sex-favorable or sex-interested. Likewise, not all sex-repulsed people are asexual. There is a small but present minority of people who are allosexual but are sex-repulsed.