Other forms: muddied
Muddy means covered in wet earth, or full of it. Boots caked after a walk across a field, paw prints down the hall, a puddle churned to brown soup by tractor tyres.
Colours go muddy when they are mixed until nothing in them is clean — a muddy brown, a muddy green. Sound goes muddy when the bass swallows everything and you cannot pick out a word. So does thinking: muddy reasoning is reasoning nobody can follow. As a verb, to muddy something is to make it dirty or to make it unclear, and to muddy the waters is to drag in something that leaves a question harder than it was. The forms are muddier and muddiest.
1adjectivemuddyCovered in or full of wet earth.
“Leave those muddy boots by the door.”
2adjectiveclearNot clear — of a colour, a sound or an idea.
“The recording is muddy and you can barely make out the words.”
3verbdirtyTo make something dirty with mud, or to make it harder to understand.
“Bringing money into it only muddies the argument.”
Muddy is simply mud with a y on the end, first written as muddi in late Middle English. Mud itself looks borrowed — from Middle Dutch and Middle Low German modde, back to Proto-Germanic *mud-, and perhaps to a Proto-Indo-European *mew- meaning moist. It is a doublet of muddle, which is what muddy water does to a clear idea.
Proto-Indo-European
*mew-
Proto-Indo-European
*mū-
Proto-Germanic
*mud-
Middle Low German
modde
Middle Dutch
modde
Middle English
muddi
English, today
muddy
Built from
The adjective is derived from Late Middle English muddi, moddy, muddy (“covered with or full of mud, muddy”), from mud, mudde (“mud; turbid water”) + -i. Mud, mudde is possibly borrowed from Middle Dutch modde, and/or Middle Low German modde, mudde, from Proto-Germanic mud-, mudra- (“mud”), possibly from Proto-Indo-European mū-, mew- (“moist”). The English word is analysable as mud + y. a doublet of muddle. The verb is derived from the adjective. 2
Etymology from Wiktionary, CC BY-SA