Definitions for "One-tailed test"
A significance test in which a statistic obtained from the data is compared to the critical value in a designated tail of the probability distribution.  Used when the alternative hypothesis specifies the sign the test statistic must achieve.  Synonymous with directional hypothesis.  Because F-ratios must be positive, ANOVA employs only one-tailed tests.
A test that rejects extreme outcomes in only one specified tail of the distribution.
a test of the prediction that one value is higher than another.