This is the 1105th most frequent Polish word.
określonych
"Specified" or "defined."
The word 'określonych' is used here as an adjective, describing the noun 'hours' (godzinach) as being specified or defined beforehand.
W tym sklepie można kupić produkty tylko w określonych godzinach.
In this store, products can only be purchased during specific hours.
The term 'określonych' serves as an adjective, defining 'conditions' (warunkach) as being specific or pre-established conditions.
Regulamin zostanie omówiony w określonych warunkach.
The regulations will be discussed under specified conditions.
In this sentence, 'określonymi' agrees with the noun 'principles' (zasadami) in number and case, describing them as specific and outlined.