from The American Heritage® Dictionary of the English Language, 4th Edition
- A trademark used for the drug sildenafil citrate.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. Trademark name of the drug, sildenafil citrate, used to treat erectile dysfunction.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. virility drug (trade name Viagra) used to treat erectile dysfunction in men
Disputed. Possibly from Sanskrit व्याघ्र (vyāghra, "tiger"). Probably suggested by words such as virile and virility. (Wiktionary)