fi ‧ del ‧ i ‧ ty /fɪˈdeləti, fɪˈdelɪti/ BrE AmE noun [uncountable] formal
[ Date: 1400-1500 ; Language: French ; Origin: fidélité , from Latin fidelitas , from fides 'faith, trust' ]
1 . when you are loyal to your husband, girlfriend etc, by not having sex with anyone else SYN loyalty OPP infidelity :
the importance of marital fidelity (=in marriage)
2 . when you are loyal to a person, an organization, or something that you believe in SYN loyalty
fidelity to
his fidelity to the company over 25 years
3 . formal how much a film, a piece of written work etc remains unchanged from an earlier piece of work, or the facts that are known SYN faithfulness
fidelity to
the movie’s fidelity to the original book
⇨ ↑ high fidelity