English acronym standing for Away With The Fairies. Despite the inclusion of the word Fairies there is no implication of homosexuality in the expression. It is merely used to describe someone who is in a world of their own either because they are daydreaming or are thinking intensely and thus are oblivious to what is going on around them. The expression goes back to an old superstition, prevalent throughout Europe that fairies, wee folk, call them what you will, could steal a person's soul, leaving behind a husk that stared at nothing until it faded away and died.
Superstition aside, it came to be applied to people who became so engrossed in their own thoughts that they ignored what was going on around them. For a while it was used as a politically incorrect medical acronym written in a patient's notes to describe someone suffering from dementia or in a highly confused state of mind for some other reason. Fortunately it has fallen into disuse medically owing to its meaning becoming known to a wider audience. Its major use now is in the workplace where it describes someone who spends time staring into space rather than doing something useful.