default

1 default /dɪˈfɑːlt/ noun
plural defaults
1 default
/dɪˈfɑːlt/
noun
plural defaults
Britannica Dictionary definition of DEFAULT
1 
[noncount] — used to describe something that happens or is done when nothing else has been done or can be done — usually used in the phrase by default
— sometimes used before another noun
2 
a  : a failure to make a payment (such as a payment on a loan)
[noncount]
[count]
b  [noncount] law : failure to appear in court
3 
[count] computers : a setting, option, etc., that a computer uses if you do not choose a different one
— often used before another noun

in default of

formal
: in the absence of (something) : without (something)
2 default /dɪˈfɑːlt/ verb
defaults; defaulted; defaulting
2 default
/dɪˈfɑːlt/
verb
defaults; defaulted; defaulting
Britannica Dictionary definition of DEFAULT
[no object]
1 
: to fail to do something that legally must be done
especially : to fail to make the payments you must make on a loan, mortgage, etc.
2 
of a computer : to automatically use a particular setting, option, etc., unless you choose a different one

— defaulter

noun, plural defaulters [count]