Translated roughly from the Dutch as “faces” or “expressions”, tronien (pl.) were a category of subject in 17th-century Dutch painting. Tronien were painted from living models, but they were not intended to be recognized as portraits. Rather, they represented interesting characters or types, such as a dashing soldier or a drunkard, often with exaggerated facial expressions. Pronunciation here. Web resource here.
Jan Lievens. Bearded Man with a Beret. Oil on panel. Ca. 1630. National Gallery of Art, Washington, D. C.