lick someone's boots
Act with extreme servility, as in This man wanted every employee to lick his boots, so he had a hard time keeping his staff. Shakespeare used this idiom in the form of lick someone's shoe in The Tempest (3:2). [Late 1500s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.