in the thick of something/of doing something

in the thick of it

Very busy; in the middle of or preoccupied with something or several things. Sorry I couldn't make it to your birthday lunch on Wednesday, I'm afraid I'm really in the thick of it at the office right now. Even when you are in the thick of it, try to take a moment each day and take a deep, calming breath.
See also: of, thick
Farlex Dictionary of Idioms.

in the thick of it

or

in the thick of something

COMMON If you are in the thick of it or in the thick of an activity or situation, you are very involved in it. Soon he was in the thick of it, chatting in three languages, kissing hands, explaining and introducing. He suddenly found himself in the thick of desperate fighting.
See also: of, thick
Collins COBUILD Idioms Dictionary, 3rd ed.

in the ˈthick of something/of doing something


1 in the busiest or most active part of something/doing something: He was in the thick of preparing the food for the party, so I didn’t interrupt.
2 in the most crowded part of something: If there’s trouble, you usually find him in the thick of it.
See also: of, something, thick
Farlex Partner Idioms Dictionary
See also:
  • a run on (something)
  • a rush on (something)
  • address (one's) comments to (someone or something)
  • address comments or remarks to
  • address (one's) remarks to (someone or something)
  • be in it for
  • be pressed for time
  • ask (something) of
  • ask of
  • be pushed for time