The eruption and cutting of teeth, especially the milk teeth; dentition.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "teething" in a sentence
"Poison in teething remedy kills 34 Nigerian children | BabyCenter"
"One thing that worked for us with teething is to wet a washcloth, then wring it out and toss it in the freezer."
"Oh your poor little bunny. teething is such an absolute misery, and to think I have one about to go into braces …"