By passing -g we to alias, we can define a global alias, which is substituted anywhere on a line (command aliases can only be substituted at the beginning of the line):
$ alias world='WORLD' # standard command alias
$ world
zsh: command not found: WORLD # looks for the alias, usual behaviour
~/.dotfiles main [127] $ echo world
world # because world is not the first word, it's alias is not triggered here.
$ alias -g world='WORLD' # make it a global alias now
~/.dotfiles main $ echo world
WORLD # boom! `world` is substituted despite not being the first word in the command!
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