repellent (n.) Look up repellent at Dictionary.com
also repellant, 1660s, "medicine that reduces tumors," from repellent (adj.). As "substance that repels insects," 1908.
repellent (adj.) Look up repellent at Dictionary.com
also repellant, 1640s, from Latin repellentem (nominative repelens), present participle of repellere (see repel). Originally of medicines (that reduced tumors); meaning "distasteful, disagreeable" first recorded 1797.