aero /ˈɛəɹəʊ/noun 3adjective 2forms 3 noun3 •(slang) Aerodynamics."The biggest difference is aero, which is a really big cut." — 2009 •Aerospace. •(informal, old-fashioned) An airplane or airship. adjective2 •Of or pertaining to aviation.We've seen a lot of growth in the aero sector. •Aerodynamic; having an aerodynamic appearance.It's a very aero design, with smooth lines. formsaeros · more aero · most aero