Green’s Dictionary of Slang

1. (US) unsophisticated, provincial.

1914		‘Hugh McHugh’ You Should Worry cap. 1: We're not a couple of Patsys with the pumps! We can learn enough in two lessons to make good in this Boob community.
1917		S. Lewis Job 151: ‘[L]eaving me sitting there with the waiter laughing his boob head off at me’.

2. (Aus.) inferior, second-rate.

1920		H.C. Witwer Kid Scanlon 81: I bet that boob mechanic left that in there.
1928		T. Thursday ‘Sock of Ages’ in Fight Stories Oct. 🌐 Now comes what most folks called the world’s premier boob stunt.
1982		H. Beaton Outside In I ii: That’s an ol’ boob joke. Been round longer than I have.