monochrome- having one color; a painting, design, photo, or outfit that is only one color or shades of one color
monocle- en eyeglass for one eye
monolingual- speaking or writing only one language
monolith- something made out of one single large block or piece of stone, one single stone monument
monologue- a long speech given by one person
monophobia- an abnormal fear of being the only one there; fear of being alone
monopoly- control of a product or service by one company
monorail- a track for subway or train cars that only has one rail
monosyllabic- having only one syllable
monotone- a speech in which every word has one tone of voice