せっかく

adverb, noun

with effort; at great pains; specially

Expresses that something was done with considerable effort or that a rare opportunity should not be wasted. Often used in phrases like せっかく～のに (even though one went to the trouble) or せっかくだから (since it's a special occasion).

• せっかく来きたのに、店みせは閉しまっていた。

  Even though I made the effort to come, the shop was closed.

• せっかくの休やすみだから、どこかへ出でかけよう。

  Since it's a rare day off, let's go out somewhere.

noun which may take the genitive case particle 'no'

rare; valuable; precious; long-awaited

Describes something that is hard to come by or a special opportunity. Often used attributively with の, as in せっかくの機会 (a rare opportunity).

• せっかくのチャンスを逃のがした。

  I missed a rare chance.

noun which may take the genitive case particle 'no'

kind; generous

Used to describe a kind or generous act, often in the phrase せっかくのご好意 (your kind offer). This sense is somewhat formal and less common in casual speech.

• せっかくのご好こう意いですが、お受うけできません。

  I appreciate your kind offer, but I cannot accept it.