This is the 2661st most frequent German word.
einzigartige
Unique.
Here, 'einzigartige' is used as an attributive adjective, modifying the noun 'Geschenk' ('gift'), and it takes the neuter singular nominative form 'ein einzigartiges'.
Das ist ein einzigartiges Geschenk.
This is a unique gift.
In this sentence, 'einzigartige' modifies the noun 'Atmosphäre' ('atmosphere'), fitting the feminine singular accusative form 'eine einzigartige'.
Die Stadt hat eine einzigartige Atmosphäre.
The city has a unique atmosphere.
Here, 'einzigartige' is part of the expression 'eine einzigartig entschlossene Haltung' ('a uniquely determined attitude'), where 'einzigartig' functions as an intensifying adjective for 'entschlossene Haltung'.