semielliptic

== English == === Etymology === From semi- +‎ elliptic. === Adjective === semielliptic (not comparable) Synonym of semielliptical. (mathematics) In the theory of partial differential equations, designating a partial differential operator satisfying a positivity condition slightly weaker than that of being an elliptic operator. This produces a curved line progressively slightly straighter than an ellipse, such as that of an automotive leaf spring.