LGBT+Q

I red the article of English Journal. LGBT became LGBTQ, +Q. "Q" is the queer. "Queer"??? The dictionary said "(especially of a man) gay:" or "strange, unusual, or not expected:". I'm not familiar with this word. Strange or unusual people is the one of the type LGBT... Diversities is very important to live together with others, especialy foreigners. I should recognize that the queer is one of the diversities. I improved.