- noun the act of making a way into or through something
- noun the percentage of a target market that accepts a product
- noun the percentage of a target audience reached by an advertisement
- An intrusion or otherwise unauthorized entry into a computer system or network. For instance, the cracking of a password using a brute force attack, followed by the obtaining of key information such as other passwords.
- noun the amount to which a given media has ‘penetrated’ the market, i.e. the number of people that use it or are able to use it