a rhetorical device in which a point is stressed by suggesting that it is too obvious or well-known to mention, as in the phrase, “not to mention the expense involved”
: also ˌparaˈlepsis (ˌpærəˈlɛpsɪs), ˌparaˈlipsis (ˌpærəˈlɪpsɪs)
Word origin
Gr, omission < para-, para-1 + leipein, to leave: see loan