take off (one's) hat (to someone or something)
To praise, salute, congratulate, or pay tribute to someone or something. We all take off our hats to Janet for her recent promotion. I take off my hat to that organization for providing help when no one else does.
take off one's hat (to someone)
Fig. to offer praise for someone's good accomplishments. I have to take off my hat to Mayor Johnson. She has done an excellent job. Yes, we all ought to take off our hats. She is our best mayor ever.