C2 adjective /ˌɪnfɪnɪˈtɛsɪməl/
infinitesimal
微不足道
Meaning
Extremely small in size or amount; so tiny as to be almost negligible.
Example
The error was so infinitesimal that it didn’t affect the results.
这个错误如此微不足道,以至于没有影响结果。