We only had enough room to pack the 'bare essentials'. [=the things that are absolutely necessary]
Reservations are 'essential' [='necessary, needed'] if you plan to eat there on a Saturday.
All action movies have 'essentially' [='basically, fundamentally'] the same plot.
(..) all you need to know is that there are... inmates in Blackgate Prison as a direct result of the Dent Act. These are violent criminals, essential... cogs in the organized-crime machine. Maybe, for now, all I should say about the death of Harvey Dent is this... it has not been for nothing. (..)2012 The Dark Knight Rises