nasty

Some common synonyms of nasty are dirty, filthy, foul, and squalid. While all these words mean "conspicuously unclean or impure," nasty applies to what is actually foul or is repugnant to one expecting freshness, cleanliness, or sweetness; in practice, however, nasty is often weakened to the point of being no more than a synonym of unpleasant or disagreeable. When used figuratively, nasty implies a peculiarly offensive unpleasantness.

The words dirty and nasty are synonyms, but do differ in nuance. Specifically, dirty emphasizes the presence of dirt more than an emotional reaction to it or, figuratively, stresses meanness or despicableness.

Although the words filthy and nasty have much in common, filthy carries a strong suggestion of offensiveness and typically of gradually accumulated dirt that begrimes and besmears. Figuratively, it can also describe disgusting obscenity.

While in some cases nearly identical to nasty, foul implies extreme offensiveness and an accumulation of what is rotten or stinking; it can also describe, for example, loathsome behavior.

In some situations, the words squalid and nasty are roughly equivalent. However, squalid adds to the idea of dirtiness and filth that of slovenly neglect. Distinctively, its figurative use implies sordidness as well as baseness and dirtiness.