निष्ठावान in English:

My great aunt was a staunch teetotaler.

staunch supporter/friend

Even staunch privacy advocates should seize this moment.

I'm very staunch if we are talking about marriage.

As a staunch European, I must therefore vote against this report.

a staunch supporter of the Communist party

Even their most staunch supporters wonder whether or not the party is making the right choices.

Dogs are loyal animals.

He was more loyal than I had guessed.

I am loyal to my family.

He was a keen sportsman and a loyal friend.

Jenny’s very loyal, she never says anything unkind.

It must be nice having such a loyal son. You don't have to wonder if you'll be taken care of in your old age.

For his length of loyal service to his organization, he was only repaid in chicken feed.

Mr. Johnson's workers are loyal to him.

Pop artists thrive on the adulation of their loyal fans.

He was loyal, just as she had said in her letter.

He wasn’t a loyal friend and revealed all my secrets to other people.

Our shop has loyal customers who come here regularly.

A loyal friend will stand by you through good and bad times.

loyal as a dog

the stalwarts of the Labour Party

he was of stalwart build