köstlich
Translation
delicious, delightful, exquisite, scrumptious
Examples
Der Kuchen schmeckt köstlich.
The cake tastes delicious.
Das war ein köstliches Essen.
That was a delicious meal.
Ich habe mich köstlich amüsiert.
I had a delightful time.
Grammar Patterns
[as an adjective] delicious ... This is a delicious wine.
[as an adverb] delightfully ... We had a delightful conversation.
Similar Words
Synonyms: lecker, schmackhaft; Antonyms: ungenießbar (inedible), scheußlich (awful)
Etymology
From 'kosten' (to taste, to cost). It implies something of high value, hence delicious or delightful.
Memory Tips
It sounds like 'costly'. Imagine a costly, and therefore delicious, meal.