To meditate; to contemplate; to consider a subject by turning it in the mind and viewing it in its different aspects and relations; as, to speculate on political events; to speculate on the probable results of a discovery.

In commerce, to purchase land, goods, stock or other things, with the expectation of an advance in price, and of selling the articles with a profit by means of such advance; as, to speculate in coffee, or in sugar, or in six percent stock, or in bank stock.

To consider attentively; as, to speculate the nature of a thing.