This is the 8956th most frequent Russian word.
радич
The word "радич" does not appear to exist in standard Russian; it may be a typo or a regional/rare term.
In this sentence, 'ради' is used as a preposition meaning 'for the sake of' or 'for' to indicate a reason or purpose for someone's actions.
Он выбрал этот путь ради семьи.
He chose this path for the sake of his family.
Here, 'ради' again acts as a preposition indicating the purpose or intended benefit of the action, which is peace.
Мы должны работать ради мира в мире.
We must work for peace in the world.
In this instance, 'ради' is similarly used as a preposition emphasizing the goal or beneficiary of the effort, which is scientific advancement.