This is the 121st most frequent Lithuanian word.
visa
The Lithuanian word "visa" means "all" or "whole" in English (feminine form).
Here, "visa" is used to mean "the entire" or "the whole", modifying "diena" (day).
Visa diena buvo saulėta ir šilta.
The whole day was sunny and warm.
Here, "visa" is modifying "savo dėmesio" (my attention), indicating the entirety of it, translating to "all" in English.
Man reikia visa savo dėmesio sutelkti į šią užduotį.
I need to focus all my attention on this task.
Here, "visa" is functioning as an adverb-like modifier, emphasizing and intensifying the adjectives "laiminga" (happy) and "linksma" (cheerful).