Very often, our customer calls us and would like to talk to my colleague. If my colleague is at lunch, I would say, “He’s at lunch,” or, “He’s away at lunch.” You can even say, “He’s taken off for lunch,” or, “He’s not back from lunch yet.” ( Ways of saying “out to lunch” ) If it’s not lunch time, and he/she is not at his/her desk, I would say, “He is not at his desk. Can I take a message?” ( He is not at his desk ) If my colleague is off sick, this will be appropriate: “he is off sick.” or "she is out sick."
One Thousand And One Nights of Dreams:-- Come True!