Definitions

1. verb

to become or make thicker, denser, or more viscous

“The sauce will thicken as it cools.”

2. verb

to make or become more intense, concentrated, or complex

“The flavors of the dish will thicken as it cooks.”

3. noun

the act of becoming or making thicker or denser

“The thickenning of the paint is slowing down.”

4. transitive verb

to make or cause to become thicker or more viscous

“Thicken the soup with a roux.”