An airline usually considers toothpaste as a gel but toothpaste does count towards the gels and liquids when flying.
You can take toothpaste on an airplane on your carry on luggage as long as it's in 3.4 ounce or smaller containers.
Toothpaste is in the category of toiletries which include lip balm, deodorant, lip stick and yes the Toothpaste and Toiletries are considered in the liquids as well when going through airport security.