By studying the suffix, the reader can determine that impetuous most likely means to be<em> impulsive, to act quickly without thought or care.</em>
Explanation:
The suffix <em>ous</em> have often been used to anglicize Latin adjectives with terminations that cannot be directly adapted into English. In this case, the word <em>impetu</em> comes from Latin, and means <em>atack</em>. <em>Impetuous</em> is an adjective that helps describe a person as maybe violent or that moves forcefully or rapidly without thinking much.