Meaning : In target shooting: a score made by hitting the center of the target.
Example :
In repeated sets of five shots his numbers of bull's-eyes varied.
Meaning : The center of a target.
Synonyms : bull
Meaning : Something that exactly succeeds in achieving its goal.
Example :
The new advertising campaign was a bell ringer.
Scored a bull's eye.
Hit the mark.
The president's speech was a home run.
Synonyms : bell ringer, home run, mark