repellent (adj.) Look up repellent at Dictionary.com
also repellant, 1640s, from Latin repellentem, present participle of repellere (see repel). Originally of medicines (that reduced tumors); meaning "distasteful, disagreeable" first recorded 1797.
repellent (n.) Look up repellent at Dictionary.com
"substance that repels insects," 1908, from repellent (adj.).