There are several synonyms for the term "egg sacs," which refers to the protective container that holds eggs laid by various animals such as spiders, insects, and amphibians. One such synonym is "ootheca," which is primarily used for referring to the egg masses of cockroaches. Another synonym is "cocoons," which refers to the protective coverings of the eggs laid by certain insects such as moths and butterflies. In addition, the term "nidament" is also used in reference to the egg masses of snails and mollusks. Overall, the synonyms for egg sacs highlight the diverse and fascinating ways in which different animals protect their offspring.