generously; freely; without stint
Used when giving, sharing, or expending effort without holding back; often implies a lack of stinginess or reluctance.
He generously shared his knowledge with me.
She spends money freely.
Common kana-mixed spelling; both forms are widely used.
From the verb 惜しむ (to begrudge, to be sparing) in its continuative form 惜しみ + 無く (adverbial form of 無い, 'not existing'), literally 'without holding back'.