The term "cackly" refers to a harsh, unpleasant, or high-pitched laugh that often seems forced or fake. Some synonyms for this word include "giggly," "snickering," "chuckling," "sniggering," and "tee-heeing." These words all describe different types of laughter that are often associated with nervousness, insincerity, or malicious intent. Other possible synonyms for "cackly" might include "cackling," "chortling," "sneering," or "jeering," all of which convey a sense of contempt or derision. While each of these words has its own nuance and connotation, they all share the common characteristic of being unpleasant or annoying to hear.