This is the 417th most frequent Lithuanian word.
didelio
The Lithuanian word "didelio" means "big" or "large" (genitive singular form).
Here, 'didelio' again is the genitive form of 'didelis', used to describe 'sodo' (garden) which itself is in the genitive case due to the preposition 'iš'.
Jis atnešė gėlę iš didelio sodo.
He brought a flower from a big garden.
In this example, 'didelio' agrees in gender, number, and case with 'projekto' (project), which is in genitive singular after 'dalis' (part), to provide the description (big).
Tai buvo dalis didelio projekto.
It was a part of a big project.
In this sentence, 'didelio' is the genitive form of the adjective 'didelis' and describes the size (big) of the object (table), complementing the noun it is modifying in the genitive case required by the preposition.