Of, printed, or formatted in lowercase letters.(adjective)
To put (type or text) in lowercase letters.(verb-transitive)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "lowercase" in a sentence
"THIS time they want the email in lowercase (makes sense)."
"Archy the cockroach wrote his name in lowercase letters because he couldn't maneuver the shift bar of Don's typewriter."
"Also — I don’t know if this is the case here — I have some recollection of having once read about some words like “nazi” deliberately being used in lowercase to show disrespect, so even if “Quisling” were grammatically correct, “quisling” would be preferred?"