(number theory) Given a positive integer m and a divisibility sequence Sₖ, the smallest index k such that Sₖ is divisible by m;

(Cockney rhyming slang) A wank.

(law) The obligation of a barrister (in certain jurisdictions) to accept any work in a field in which they profess themselves competent to practise, at a court at which they normally appear, and at their usual rates.

(linear algebra) A theorem about linear transformations (or the matrices that represent them) stating that the rank plus the nullity equals the dimension of the entire vector space (which is the linear transformation’s domain).

plural of cab off the rank

(Australia) Something fitting or occurring at a specified point in a series.

(chess) A checkmate delivered by a major piece along the back rank against a king whose advancement is prevented by pieces of its own color (most commonly pawns).

Of the highest rank

plural of flag rank

At an important, elevated, or exalted level in a hierarchy or organization; high-level.