abstain

1 ENTRIES FOUND:
abstain /əbˈsteɪn/ verb
abstains; abstained; abstaining
abstain
/əbˈsteɪn/
verb
abstains; abstained; abstaining
Britannica Dictionary definition of ABSTAIN
[no object]
1 
: to choose not to do or have something — usually + from
2 
: to choose not to vote

— abstainer

noun, plural abstainers [count]