Homophobia is a term used to describe hatred and rejection of gay people. As defined in most dictionaries, homophobia is the fear of, aversion to, or discrimination against homosexuality or homosexuals. It can also mean hatred of and disparagement of homosexual people, their lifestyles, sexual behaviors or cultures, and is generally used to assert bigotry.

When the term is applied to political or religious opposition to specific sexual acts or political positions, it has been criticized as a pejorative, loaded term intended to discredit or silence opposition to any of the political or social issues connected with homosexuality (see LGBT social movements). Critics of the term have often alleged that it creates a climate of intimidation by demonizing one side of the debate.

Xenophobia denotes a phobic attitude toward strangers or of the unknown. It comes from the Greek words ξένος (xenos), meaning "foreigner," "stranger," and φόβος (phobos), meaning "fear." The term is typically used to describe fear or dislike of foreigners or in general of people different from one's self. For example, racism is sometimes described as a form of xenophobia, but in most cases racism has nothing to do with a real phobia. In science fiction, it has come to mean "fear of extraterrestrial things." Xenophobia implies a belief, accurate or not, that the target is in some way foreign. Prejudice against women cannot be considered xenophobic in this sense, except in the limited case of all-male clubs or institutions. The term xenophilia is used for the opposite behavior, attraction to or love for foreign persons.

The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, 4th edition ("DSM-IV") includes in its description of a phobia an "intense anxiety" which follows exposure to the "object of the phobia, either in real life or via imagination or video..." For xenophobia there are two main objects of the phobia. The first is a population group present within a society, which is not considered part of that society. Often they are recent immigrants, but xenophobia may be directed against a group which has been present for centuries. This form of xenophobia can elicit or facilitate hostile and violent reactions, such as mass expulsion of immigrants, or in the worst case, genocide.

The second form of xenophobia is primarily cultural, and the object of the phobia is cultural elements which are considered alien. All cultures are subject to external influences, but cultural xenophobia is often narrowly directed, for instance at foreign loan words in a national language. It rarely leads to aggression against persons, but can result in political campaigns for cultural or linguistic purification. Isolationism, a general aversion of foreign affairs, is not accurately described as xenophobia.

Ephebiphobia (from Greek 'ephebos' έφηβος = teenager, underage adolescent and 'fobos' φόβος = fear, phobia), also known as hebephobia (from Greek 'hebe' (ήβη) = youth), denotes both the irrational fear of teenagers or of adolescence, and the prejudice against teenagers or underage adolescents. It is essentially a social phobia comparable to xenophobia or homophobia. The word is a neologism of very recent creation.

Agoraphobia is a form of anxiety disorder. Sufferers of agoraphobia fear crowded situations, especially in a confined space, where anxiety may escalate into panic attacks. As a result, sufferers of agoraphobia are often confined to their homes and face difficulty traveling to the outdoors.