micronova UK /ˈmaɪ.kɹo.nəʊ.və/US /ˈmaɪ.kɹo.noʊ.və/ noun1 •A stellar outburst about one millionth the strength of a classical nova.The pressure eventually overcomes the outer shell, erupting in a micronova. — 2021 formsmicronovae · micronovas