erc-keyword-highlight-type

erc-keyword-highlight-type is a variable defined in `erc-match.el'.
Its value is

keyword

Documentation:
Determines how to highlight messages containing keywords.
See variable `erc-keywords'.

The following values are allowed:

'keyword - highlight keyword only
'all - highlight the entire message containing keyword

Any other value disables keyword highlighting altogether.

You can customize this variable.