Should you feel that a family member, colleague, friend, or neighbor is acting in a strange manner, contact the Magical Law Enforcement Squad at once.
We are here to persuade an old colleague of mine to come out of retirement and return to Hogwarts.
Professor, why couldn’t we just Apparate directly into your old colleague’s house?
Harry, this is an old Friend and colleague of mine, Horace Slughorn.
Harry wondered why Dumbledore did not consider it rude to call on his old colleague so late, but now that conversation had been established, he had more pressing questions to ask.
However, he had the sense never to try and charm me as he charmed so many of my colleagues.
"We are pleased to welcome a new member of staff this year, Professor Slughorn"— Slughorn stood up, his bald head gleaming in the candlelight, his big waistcoated belly casting the table into shadow — "is a former colleague of mine who has agreed to resume his old post of Potions master."
The death of the headmaster at the hands of one of our colleagues is a terrible stain upon Hogwarts’s history.
There are no more uses of "colleague" in the book.
Show samples from other sources
The surgeon consulted his colleagues.
I’m not the smartest fellow in the world, but I can sure pick smart colleagues.