This is the 566th most frequent Lithuanian word.
pirmąjį
The Lithuanian word "pirmąjį" means "the first" (accusative singular form).
In this sentence, 'pirmąjį' is used as a numeral adjective indicating sequence, describing 'first time'.
Pirmąjį kartą apsilankiau Vilniuje praėjusiais metais.
I visited Vilnius for the first time last year.
Here, 'pirmąjį' serves to designate the initial instance of a specific achievement (making a cake).
Jis pagamino pirmąjį savo gyvenime tortą.
He made the first cake of his life.
'Pirmąjį' in this context refers to the initial person in an ordered sequence.