1
general::
Phrase(s): take someone aside
to remove someone temporarily from the group for the purposes of discussing something privately. • I’m sorry he insulted you. I’ll take him aside and talk to him about it. • I took aside my secretary and explained the procedure.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Also, take to one side. Talk to another privately or away from others, as in The doctor took Pat aside to explain what she had to do, or The boss took William to one side rather than criticize his work in front of his colleagues.
American Heritage Idioms