fi·del·i·ty

/fəˈdɛləti/ noun [noncount]

1 a : the quality of being faithful to your husband, wife, or sexual partner

She began to doubt her husband's fidelity. [=to wonder if he was having an affair with another woman]

sexual fidelity

— often + to

his fidelity to his wife

opposite ↑infidelity

1 b : the quality of being faithful or loyal to a country, organization, etc.

— usually + to

No one can doubt his fidelity [=devotion] to his country.

2 : the degree to which something matches or copies something else

— + to

The movie's director insisted on total fidelity to the book. [=insisted that the story told in the movie should accurately copy the story told in the book]

3 : the degree to which a device (such as a CD player, radio, or television) correctly reproduces sounds, pictures, etc.

music with much higher fidelity than on cassettes

a printer with outstanding color fidelity [=a printer that produces very accurate colors]

— see also ↑high fidelity