Synonym of cloud nine.

(complex analysis) An imaginary number.

(mathematics) Any of several complex numbers that are coordinates of the vertices of a regular polygon of unit radius

(genetics) A DNA sequence, 1000 nucleotides (or synonymously base pairs) in length or longer, that is present a variable number of times as copies in a genome relative to a reference genome.

A unique number assigned by IANA to identify objects that are defined by an enterprise.

(genetics) The variation of the number of copies (normally two) of a gene, or of sequences of DNA, in the genome of a specific individual; has been linked to some diseases

(genetics) The normal variation in the number of copies (normally two) of a gene, or of sequences of DNA, in the genome of a specific individual

(US) A pencil which produces a specific shade of dark gray. One can usually identify a number 2 pencil by looking for the number "2" conspicuously emblazoned on the pencil. Often required for test-taking and the completion of official forms.

(graph theory) The number of edges in a minimum edge cover of a graph, often denoted as 𝜌=𝜌(G).

(physics) A Reynolds number at which the flow of a fluid changes from laminar to turbulent.