muck
     n 1: any thick messy substance [syn: {sludge}, {slime}, {goo}, {gook},
           {guck}, {gunk}, {ooze}]
     2: fecal matter of animals [syn: {droppings}, {dung}]
     v 1: remove muck, clear away muck, as in a mine
     2: spread manure, as for fertilization [syn: {manure}]
     3: soil with mud, muck, or mire; "The child mucked up his shirt
        while playing ball in the garden" [syn: {mire}, {mud}, {muck
        up}]
Source: WordNet® 2.0

MUCK
     Multi-User Chat Kingdom (MUD)
     
     
Source: Virtual Entity of Relevant Acronyms