adj. Marked by a lack of neatness or order; untidy: a sloppy room. adj. Marked by a lack of care or precision; slipshod: sloppy use of language. adj. Informal Oversentimental; gushy.adj. Of, resembling, or covered with slop; muddy or slushy: sloppy ground. adj. Watery and unappetizing: a sloppy stew. adj. Spotted or splashed with liquid.