This is the 282nd most frequent Slovenian word.
velika
"Velika" means "big" or "large" in English.
Here, 'velika' modifies 'zahvala' (thanks), indicating significant gratitude.
Velika zahvala vsem, ki so pomagali.
Great thanks to all who helped.
Here, 'velika' is used as an adjective to describe the size of the house (hiša).
Velika hiša stoji na hribu.
The big house stands on the hill.
In this context, 'velika' emphasizes the magnitude or severity of the mistake (napaka).