cast a slur

See: smear
References in classic literature ?
"Nay, it would ill become me to cast a slur upon a lady who is both my guest and the wife of my comrade-in-arms," said the Seneschal of Villefranche.
The metaphor irritated Philip, because it assumed for the speaker a romantic attitude and cast a slur upon the position which Philip instinctively felt had more to say for it than he could think of at the moment.
JUSTICE Minister Michael McDowell last night rejected claims he had cast a slur on the Garda by proposing a ban on officers giving information to journalists.