what makes one tick

what makes one tick idiom
What makes one function characteristically, what motivates one, as in We've never figured out what makes these chess players tick. This expression alludes to tick in the sense of “function as an operating mechanism, such as a clock.” [Colloquial; first half of 1900s]

The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Comments
Improve this definition.
Do you have more to add? Share your linguistic knowledge or observation.
/Register to save your comments.