Incisive, trenchant, clear-cut, cutting, biting, crisp are applied to utterances, thoughts, style, or mentalities and mean having or manifesting the qualities associated with sharpness, keenness, and acuteness, especially of mind.
Incisive usually implies not only qualities in the thing so described which give it the power to penetrate, pierce, or cut through but also the production of such an effect upon the person impressed; thus, an incisive voice or tone of voice is one that is not only sharply clear and edged but one that affects the nerves of the ear as though it were cutting into them; an incisive command is so sharply imperative and direct that it can neither be misunderstood nor disobeyed.
Trenchant carries a stronger implication than does incisive of cutting so as to define differences, categories, or classes with sharpness and perfect clearness or of probing deeply into the inmost nature of a thing so as to reveal what is hidden or concealed.
Clear-cut is applied chiefly to the effect of the qualities which make for penetration, incisiveness, trenchancy, or accuracy; it suggests sharp chiseling, clear definition, or distinct outlines, and the absence of all soft edges, haziness, or confusion in the thing or things so described.
Cutting is often used in place of incisive when a less pleasant or less agreeable quality or effect is to be connoted; the term frequently suggests sarcasm, acrimony, asperity, or harshness that wounds or hurts, but it sometimes carries a hint, at least, of such mental qualities as penetrating truthfulness and acute discernment.
Biting, when it is applied to utterances, expressed ideas, or style, suggests a power to grip and deeply impress itself on the mind or memory; it therefore often suggests a caustic or mordant quality.
Crisp (see also FRAGILE 1 ) suggests not only incisiveness but either vigorous terseness of expression or a bracing, invigorating quality.