It's a slang word that describes a group of more than two sexual partners who engage in oral sex on one another in a chain setting. This sexual act derives its name from a daisy chain because those involved in it look like a garland of flowers attached by their stems.
In this kind of sexual setup, person A engages in oral sex with person B, and person B performs oral sex on person C, who then performs oral sex on partner D and so forth, thereby forming a chain going on down to the last person who in turn does oral sex on person A. Every participant can give and receive oral sex simultaneously.
In short, oral sex reaches out to the next person until everyone in the group is working on each other to create a chain of sexual activities all at the same time.
A daisy chain can be female only, male only or inclusive of both sexes.
There’s a variation to this sexual act. It’s called “spit roast” whereby three participants (normally a woman and two men). This concept can also work perfectly well with all homosexual males. One person in the center of this group is penetrated in the ass or vagina by one partner as he or she engages in oral sex with the other.
In another variant, the participants in the chain stimulate each other using their hands, in place of oral sex. both bisexual or homosexual men have the option of taking part in a version whereby every person in the chain group penetrates the other’s ass.