authorization C2+

/ˌɔθɚrɪˈzeɪʃən/ official permission or sanction to do something

authoritarian C2+

/əˌθɔrɪˈtɛriən/ favouring strict obedience to authority over personal freedom

augment C2+

/ɔɡˈmɛnt/ to make greater by adding to; to increase

auctioneer C2+

/ˌɔkʃəˈnɪr/ a person who conducts sales by auction

augmentation C2+

/ˌɔɡmɛnˈteɪʃən/ the action or result of making something greater in size or amount

authorship C2+

/ˈɔθɚˌʃɪp/ the fact or identity of having written a particular work