These words all apply to something that is less than good, and they all express in varying degrees a sense of disappointment or dissatisfaction. Mediocre is the most general, and suggests disappointment at the undistinguished quality of a thing. Calling a performance of a play mediocre means that the performance was neither very good nor very bad, but suggests that one had expected it to be better. Mediocre , then like the rest of these words, is a relative term; and it may, like most of the others, be preceded by a qualifying adverb, such as only or just, to emphasize its disparaging implications.

• Considering her reputation as a gourmet, the dinner she served was only mediocre .

Ordinary and commonplace are probably closet to mediocre in meaning, but ordinary is broader in application and usually expresses a somewhat less severe judgement.

• How was the book? Nothing very exciting, just ordinary .

Ordinary can also mean simply uneventful, in which case it connotes no disparagement at all: an ordinary summer day, with a cloudless sky and the hum of insects in the air. Commonplace stresses the disparity between one’s expectation of originality or uniqueness and the disappointingly ordinary or vulgar reality. It often expresses the haughtiness or arrogance of one who has high standards or a keenly critical attitude.

• It was a commonplace observation – anyone might have made it.

Fair and so-so are close synonyms. Both occur rather more often in speech than in writing, and are thus somewhat more informal in tone than mediocre and ordinary. Depending on the context (or tone of voice with which they are uttered), fair and so-so can range from cautious approval to moderate disgust. They are often deliberately used in a non-committal way, as to conceal bad news or a low opinion, often out of politeness or from the wish to keep one’s own affairs private.

• How do you feel now, after your operation? Oh, so-so ; How did you like the book I lent you? It was pretty fair .

Fair is also used as a rank in a grading scale: excellent, good, fair , poor.

Passable and tolerable are both examples of damning with faint praise. Passable suggests bare adequacy; it expresses the attitude indicated by a shrug of the shoulders and the comment, "Well things could be worse." If something is passable , one is simply forced to make do with it out of necessity rather than choice.

• She didn’t really like the hat, but it was passable , and it couldn’t be exchanged; The film was just passable – there were one or two good scenes, but the acting was bad and the plot fell apart near the end.

Tolerable has a wider range of meaning than passable . While it may mean barely adequate, it does not always emphasizes barely, as passable does, but may in fact emphasize adequate.

• It was a tolerable salary, one you could live on if you knew how to keep a budget.

Second-rate , especially when opposed to first-rate, is the most obviously derogatory of the words in this group; but when it is used in a scale of values that includes even lower categories, it has milder meaning.

• It’s a good second-rate school, strong in some departments and weak in others, but certainly better than a great many other schools in this area.