The crossword solution for the term 'HISSED 'YO!' is PSST, which is an interjection used to get someone's attention without alerting others nearby. It is typically used in a whisper and is often accompanied by a gesture such as a finger to the lips. The phrase 'HISSED 'YO!'' is an example of how this interjection is used, with the speaker hissing the word 'yo' to get the attention of the person they are addressing.