This is the 527th most frequent Croatian word.
ljubavi
"Love" (used as a term of endearment or in the context of affection).
The word 'ljubavi' is the vocative singular form of 'ljubav' (love), used as a term of endearment when addressing someone loved.
Moja ljubavi, koliko te volim.
My love, how much I love you.
Here, 'ljubavi' is the genitive singular form of 'ljubav' (love), used to express a quantity or lack of love.
Život bez ljubavi nema smisla.
Life without love has no meaning.
In this case, 'ljubavi' is the plural nominative or genitive form of 'ljubav' (love), describing days full of love or memories.