posynomial

Noun

 * 1)  A  of the form $$f(x_1, x_2, \dots, x_n) = \sum_{k=1}^K c_k x_1^{a_{1k}} \cdots x_n^{a_{nk}}$$, where all the coordinates $$x_i$$ and coefficients $$c_k$$ are positive real numbers, and the exponents $$a_{ik}$$ are real numbers.