Tzaddik - Hebrew singular noun for the 'Righteous One"
Tzaddikim - Hebrew plural noun - Students of Righteousness - people with a learners permit. When I was a teacher, I noticed something about students, "They sometimes fail." Eventually though, if they keep tryin, they get it.
"All your people will be 'tzaddikim;'
they will inherit the land forever;
they will be the BRANCH I planted,
my handiwork, in which I take pride.
"The smallest will grow to a thousand,
the weakest will become a mighty nation.
I, Adonai, when the right time comes,
will quickly bring it about.”
Isaiah 60:21-22 Complete Jewish Bible
( Didn't Paul say something about a BRANCH? )