Imprecise language in corporate disclosures can convey valuable information on firms' fundamentals during uncertain times. To evaluate this idea, we develop a novel measure of linguistic imprecision based on sentences marked with the 'weasel tag' on Wikipedia. Using our imprecision measure, we find that the percentage of imprecise language in 10-Ks 1) predicts positive abnormal returns, 2) reduces future information asymmetry, and 3) predicts positive earnings surprises. Our findings imply that the imprecise language in 10-Ks contains new information on positive but yet immature prospects of future cash flow, and that market participants initially under-react to it possibly due to its embedded immaturity but eventually digest it.​