aQ

aq is a two-letter sequence that appears in several specialized contexts rather than as a standalone word. In scholarly and technical writing, it is most commonly encountered as an abbreviation rather than a term with its own meaning.

In chemistry, aq denotes an aqueous solution, meaning a substance is dissolved in water. It is appended to chemical formulas to indicate solubility or the medium of a reaction. For example, NaCl(aq) indicates sodium chloride dissolved in water. This usage is standardized in chemical notation and helps distinguish reactions occurring in water from those in other media.

In the realm of internet infrastructure, .aq is the country code top-level domain (ccTLD) associated with Antarctica. The code AQ corresponds to the ISO 3166-1 alpha-2 designation for Antarctica, and the .aq domain is reserved for use related to the region. Because Antarctica has no resident government or commercial infrastructure, the .aq domain is rarely used in practice, and registrations are largely symbolic or institutional for research stations and related organizations.

Other uses of aq are less standardized and vary by discipline. As a general rule, readers should rely on context to interpret the meaning, since aq can appear as an abbreviation in different fields or as part of larger notations. Overall, aq functions primarily as a shorthand symbol within specialized domains rather than as a lexical item with a broad, established dictionary meaning.