The love that dare not speak its name is a phrase from the last line of the poem "Two Loves" by Lord Alfred Douglas, written in September 1892 and published in the Oxford magazine The Chameleon in December 1894. It was mentioned at Oscar Wilde's gross indecency trial and is usually interpreted as a euphemism for homosexuality.[1]
In Wilde's definition, "the love that dare not speak its name" was:
[S]uch a great affection of an elder for a younger man [...] such as Plato made the very basis of his philosophy [...] It is that deep, spiritual affection that is as pure as it is perfect [...] There is nothing unnatural about it. It is intellectual, and it repeatedly exists between an elder and a younger man, when the elder man has intellect, and the younger man has all the joy, hope and glamour of life before him.[2][3]