Mac OS X Yosemite - Turn off the trackpad look up feature
The trackpad lookup feature of Mac OS X Yosemite allows you to search for the meaning of a word, simply by selecting it and tapping with 3 fingers on the trackpad.
To disable this feature:
- Click on the Apple menu > System Preferences.
- Click on Trackpad.
- Go to the Point & Click section.
- Uncheck Look up - Tap with three fingers.