This is the 10553rd most frequent Russian word.
вкусного
"Вкусного" means "tasty" or "delicious" (genitive or accusative case, neuter singular or masc./neuter singular in informal speech).
The word 'вкусного' is used here as an adjective in its masculine singular genitive form modifying 'пирога'.
Я попробовал кусок вкусного пирога.
I tried a piece of delicious pie.
The adjective 'вкусного' modifies 'вина' in its neuter singular genitive form, implying that the wine has appealing taste.
У нас осталось немного вкусного вина.
We have some tasty wine left.
In this example, 'вкусного' describes 'блюда' as a masculine singular genitive form describing the quality of the dish being discussed.