(computing) Contraction of x86-64.

Alternative spelling of x86-64

In Tibetan cuisine, dough stuffed with shredded turnips and dry curd cheese and cooked with bone soup.

(computing) A superset of the x86 instruction set architecture, providing additional support for 64-bit addressing while remaining mostly backward compatible with older applications.

(biology) The system that determines the sex of offspring among grasshoppers, crickets, cockroaches, and some other insects, in which females have two sex cells (XX) and males have only one sex cell (X0, or simply X; the 0 signifies the lack of another X).