Computability & Complexity / Terminology / Big-Omega {} frontmatter frontmatter Copy × title: "Big-Omega" Big-Omega Definition. f(n)=Ω(g(n))f(n) = \Omega(g(n))f(n)=Ω(g(n)) means there exist a constant c>0c > 0c>0 and a threshold n0n_0n0 such that for every n≥n0n \geq n_0n≥n0, f(n)≥c⋅g(n)f(n) \geq c \cdot g(n)f(n)≥c⋅g(n): eventual domination from below. It is Big-O with the inequality reversed; holding in both directions at once is Big-Theta. Defined in Lecture 9. Created Jul 29, 2026 · Updated Aug 25, 2026