Short for デフォルト (deforuto).

setup; establishment; creation / (computing) configuration / (narrative) setting / (narrative, fiction) in-universe information (of a character, the background, or any part of a fictional universe)

to set up; to establish; to create / (computing) to configure

to use / to employ / to make use of, to apply / to spend

software / video game

extraordinary, unusual

emergency

very; extremely / exceedingly; tremendously

(software) free software (software that can be freely copied and modified)

(computing, dated) antivirus software