What does Hams mean?
Tajweed groups several letters together as huroof al-hams because air passes audibly through them; pronouncing these letters with proper hams keeps their character distinct from letters pronounced with a fuller, closed sound.
Tajweed Rule
Hams
هَمْس · /hæms/
Hams is the soft, breathy airflow that escapes when pronouncing certain Arabic letters that lack full vocal closure.