ASY or Asy may mean:
Asymmetric warfare (or asymmetric engagement) is war between belligerents whose relative military power differs significantly, or whose strategy or tactics differ significantly.
Asymmetric digital subscriber line (ADSL) is a type of digital subscriber line (DSL) technology, a data communications technology that enables faster data transmission over copper telephone lines rather than a conventional voiceband modem can provide.
In analytic geometry, an asymptote (/ˈæsɪmptoʊt/) of a curve is a line such that the distance between the curve and the line approaches zero as they tend to infinity.
Asynchronous transfer mode (ATM) is, according to the ATM Forum, "a telecommunications concept defined by ANSI and ITU (formerly CCITT) standards for carriage of a complete range of user traffic, including voice, data, and video signals".
In mathematics, an asymmetric norm on a vector space is a generalization of the concept of a norm.
Asymmetric hydrogenation is a chemical reaction that adds two atoms of hydrogen preferentially to one of two faces of an unsaturated substrate molecule, such as an alkene or ketone.
The United States recognizes the right of asylum of individuals as specified by international and federal law.
An asymmetric cell division produces two daughter cells with different cellular fates. This is in contrast to symmetric cell divisions which give rise to daughter cells of equivalent fates.
In computer science, asynchronous I/O, or "Non-sequential I/O" is a form of input/output processing that permits other processing to continue before the transmission has finished.