Formal:
* Insignificant: This is a close synonym for negligible, meaning "too small to be worth considering".
* Trivial: Similar to insignificant, but can also imply that something is unimportant or commonplace.
* Minimal: Emphasizes that something is extremely small in quantity or amount.
* Infinitesimal: Used for something extremely small, almost nonexistent.
* Unimportant: Focuses on the lack of consequence or significance.
* Unnoticeable: Emphasizes that something is so small it is practically invisible.
Informal:
* Tiny: Simple and direct, meaning very small.
* Small: A general term, meaning not large.
* Nothing: Indicates that something is essentially nonexistent.
* Zero: Emphasizes the complete lack of something.
* Nullified: Used when something has been effectively reduced to nothing.
Other:
* Insubstantial: Implies a lack of weight or importance.
* Worthless: Highlights the lack of value.
* Negligible: This is the most direct and precise synonym for negligible.
The best word to use will depend on the context and what you want to emphasize.