gibberellin
noun
gib·ber·el·lin ˌji-bə-ˈre-lən 
: any of several growth-regulating plant hormones that promote cell elongation and activity of the cambium, induce parthenocarpy, and stimulate synthesis of nucleic acids and proteins
Example Sentences
Recent Examples on the Web The seed has two hormones: abscisic acid (ABA), which sends the signal to stay dormant, and gibberellin (GA), which initiates germination. 
Jason Daley, Smithsonian, 9 June 2017 The seed has two hormones: abscisic acid (ABA), which sends the signal to stay dormant, and gibberellin (GA), which initiates germination. Jason Daley, Smithsonian, 9 June 2017
Jason Daley, Smithsonian, 9 June 2017 The seed has two hormones: abscisic acid (ABA), which sends the signal to stay dormant, and gibberellin (GA), which initiates germination. Jason Daley, Smithsonian, 9 June 2017 Word History
Etymology
New Latin Gibberella fujikoroi, fungus from which it was first isolated
First Known Use
1939, in the meaning defined above