General synonyms:
* Mum: This is the most common informal name for chrysanthemums.
* Hardy mum: This term specifically refers to a type of chrysanthemum that's hardy in colder climates.
* Chrysanth: A less common alternative, but still a synonym.
More descriptive synonyms:
* Autumn flower: This emphasizes the time of year they typically bloom.
* Pot mum: This refers to chrysanthemums grown in pots.
* Decorative flower: This highlights their use for decoration.
The best synonym will depend on the specific context in which you're using it.