One's romantic partner, regardless of marital status or gender. / A person with whom one has an important bond of some kind.

The symbol @, most commonly used in e-mail addresses.

The eighteenth letter of the Classical and Modern Greek alphabets, the twentieth letter of Old and Ancient. / (mathematics) The symbol Σ, used to indicate summation of a set or series.

A symbol (=) used in mathematics to indicate that two values are the same, and elsewhere in various other ways, such as (formerly) to separate the signature from the content of a telegram.

The symbol $, used to indicate a price in dollars.

A sequence of states representing an encoded message in a communication channel. / Any variation of a quantity or change in an entity over time that conveys information upon detection.

(transitive, intransitive) To indicate; to convey or communicate by a signal. / (transitive) To communicate with (a person or system) by a signal.

Standing above others in rank, importance, or achievement.

(music) An indication of the key of a composition, giving the number of sharps or flats in the corresponding scale.

(mathematics) Any symbol (in particular ÷ or / ) used to denote the operation of division.