outfit (n): a set of clothes worn together, especially for a special occasion:
informal/a group of people who work together as a team or organization:
British English/a set of equipment that you need for a particular purpose or job [= kit]:
to bring up: to rear, to raise from childhood(S); to mention, to raise an issue, to introduce a topic (S)
to be the matter: to be unsatisfactory, to be improper, to be wrong
In a question, this idiom is used with what or something. In an answer, something or nothing is usually used.
to break the news: to deliver new, usually upsetting, information
to hold still: not to move (S)