thick·en 
/ˈθɪkən/ verb
thick·ens; thick·ened; thick·en·ing /ˈθɪkən/ verb : to make (something) thick or thicker or to become thick or thicker [+ obj] ▪ I thickened the gravy with flour. [no obj] ▪ When the mixture thickens, add the remaining ingredients. ▪ The fog thickened when night fell.
the plot thickens — see 1plot
— thick·en·er /ˈθɪkənɚ/ noun, plural thick·en·ers [count]
▪ Flour/cornstarch is used as a thickener in sauces.
/ˈθɪkənɚ/ noun, plural thick·en·ers [count] ▪ Flour/cornstarch is used as a thickener in sauces.
