know-it-all
/ˈnəʉ.ɪt.oːl/noun
University
1
Someone who claims to be knowledgeable or an expert in something, obnoxiously dismissing the opinions, advice, suggestions, etc. of others.
Thesaurus
#derogatory
Someone who claims to be knowledgeable or an expert in something, obnoxiously dismissing the opinions, advice, suggestions, etc. of others.