Now when I first saw this word, I thought for sure it was related to ubiquitous, which is a fun Weighty Word. However, I was wrong in this assumption. Where ubiquitous comes from the Latin word ubīqu(e) meaning everywhere, iniquitous come to us from the Latin word inīqu(us) meaning uneven or unfair. So we see they will have vasty different meanings.
iniquitous: adj. Characterized by iniquity; wicked.
ubiquitous: adj. Being or seeming to be everywhere at the same time; omnipresent.
I came across this word researching sugar-based biofuels. “[Farmers] have not been paid what they were promised. Payments have been erratic and iniquitous, with some farmers getting full payment at old rates, while others not paid at all.”
“iniquitous.” The American Heritage® Dictionary of the English Language, Fourth Edition. Houghton Mifflin Company, 2004. 20 Oct. 2008. http://dictionary.reference.com/browse/iniquitous>.
“ubiquitous.” The American Heritage® Dictionary of the English Language, Fourth Edition. Houghton Mifflin Company, 2004. 20 Oct. 2008. http://dictionary.reference.com/browse/ubiquitous>.