This is the 185th most frequent Croatian word.
tog
The Croatian word "tog" means "that" (genitive case of "to").
In this sentence, 'tog' is coupled with 'lijepog cvijeta' (beautiful flower in genitive singular masculine form), tailoring to the noun and its descriptive qualities.
Volim miris tog lijepog cvijeta.
I love the smell of that beautiful flower.
Here, 'tog' is used in its genitive singular masculine form as a demonstrative adjective, specifying the noun 'događaja' (event).
Sjećam se tog događaja kao da je bilo jučer.
I remember that event as if it were yesterday.
Here, 'tog' modifies 'pisma' (letter in genitive singular neuter form), to specify and provide context to the referenced noun.