catnip

Short definition from Wiktionary

Noun

1. 1
   Any of the about 250 species of flowering plant of the genus Nepeta, family Lamiaceae, certain of which are said to have medicinal qualities.
2. 2
   Nepeta cataria and Nepeta grandiflora (and perhaps other species), which are well-known for causing an apparently harmless pheromone-based intoxication among certain cats.
3. 3
   Something that causes excitement or interest.