How can I delete saved commands from Terminal?
It's not a Mac OS feature but a shell feature. Assuming that you are using bash (the default):


the command history is stored in memory and persisted in a file (usually ~/.bash_history)
you can list and edit the history with the history command


With man bash (in the SHELL BUILTIN COMMANDS section) you will find the description of the different options.

You can:


list the history entries

$ history

delete the whole history

$ history -c

delete a given entry

$ history -d offset