put on one's thinking cap

Think or reflect seriously, as in A new slogan? I'll have to put on my thinking cap for that. This term originated in the late 1800s and replaced considering cap, which dates from the early 1600s.

Common Names:

Name	Pronounced	Usage
Carleton	KAHRL-tən	English
Theodoricus	-	Ancient Germanic (Latinized)
Menodora	-	Ancient Greek
Nthanda	-	Southern African, Tumbuka
Josiah	jo-SIE-ə (English)	Biblical, English
Izaro	-	Basque