Sagacious.

1

1818.  The slimmest gentleman in York would not come to his store if coloured men were let in.—H. B. Fearon, ‘Sketches of America,’ p. 59. (For fuller quotation see BOSS.)

2

1848.  

        It did n’t make no diff’rence, though; I wish I may be cust,
Ef Bellers wuz n’t slim enough to say he would n’t trust!
Lowell, ‘Biglow Papers,’ No. 9.    

3