Strictly speaking something that is “ostensive” demonstrates something clearly and directly. By extension, this often is used to mean a definition that points to instances of the given concept. Even if one cannot clearly define the item in the abstract, such a definition does at least indicate clearly certain instances. The word is derived from the Latin “ostendere,” which means not only to show but also to point out; hence the applicability of the usage in our sentence.

As the young man was unable even to play the instrument, we could say that he lacks “competence” at the skill. The word is related to a number of “-pet” words, which are derived from the Latin root word for “to seek or attack.” Related English words are “petition,” “repetitive,” and so forth.

The derivation of the word’s meaning has been rather extended, however, by the prefix “com-,” which means with. One can see the meaning of these two roots more easily in the related “competition”—seeking with, in the sense that in a competition, the competitors are together seeking the same victory.

The expression here is metaphorical, so the knowledge of vocabulary is key. Isidore’s “glassy” stare could also be called “vitreous,” which means like glass. It is derived from the Latin word vitrum, meaning glass.

Since one can make quite a bit of money selling salt-water in the town, it is a rather profitable or lucrative business. This is derived ultimately from the Latin word lucrum, which means gain, profit, or even excessively greedy. The English word “lucre”, meaning money—particularly with connotations of being gained dishonorably, is from the same base.

To be “provincial” means to be from the provinces outside of a main city. Often, the added implication of the adjective is that such people are narrow-minded because they are unexposed to the supposed sophistications of city life.

The key word is “hale,” meaning strong or healthy. The focus therefore is upon Kenneth’s physical safety in spite of his bad habits of not paying heed to the traffic; therefore, the best word would be “unscathed”, meaning without experiencing harm or injury.

To be without stain is to be “immaculate.” The word comes from the Latin word “macula,” meaning stain or spot. The negative prefix “im-” indicates that the person is free from spots or stains.

Strictly speaking, to be “languid” is to lack the inclination or desire to undertake physical exertion. It therefore often has a certain negative overtone to it (implying laziness of some sort); however, it can also mean that someone is weak from sickness, as in this case.

Related English words are “languish” and “languor.”

If something is “sylvan,” it is related to forests or trees. The word ultimately is derived from the Latin “silva,” meaning forest. Its related English words are rarely used in daily discourse: “silviculture” (meaning the practice of maintaining forests) and “silvology” (meaning the study of forests).

If a group is unfamiliar with the outside world, they are often isolated in their mental habits. Such a group is called “insular” because they live as though they were on an island. The word “insular” is indeed derived from the Latin word for “island,” namely, “insula.” Related English words are “insulation” and “peninsula.”