A group of one or more species derived from a sequential development pattern which involves continual and uniform changes from an extinct ancestral form on an evolutionary scale.

simple past tense and past participle of skid

(idiomatic, informal) To profit greatly; to get an excessively good deal

(mathematics) the symbol ∓, meaning minus or plus, used alongside the plus-minus sign to show that a negative value is to be taken where the positive value is indicated by the plus-minus sign, an...