An assiduous person works hard to ensure that something is done properly and completely.

When you are astringent towards someone, you speak to or write about them in a critical and hurtful manner.

Something austere is simple and plain in its style; an austere person is strict and severe with themself.

The adjective blithe indicates that someone does something casually or in a carefree fashion without much concern for the end result; as a result, they are happy and lighthearted.

If you describe a system or process as byzantine, it means that you are criticizing it because it is excessively complicated and difficult to understand.

If you are circumspect, you are cautious; you think carefully about something before saying or doing it.

A conjecture is a theory or guess that is based on information that is not certain or complete.

Something convoluted, such as a difficult concept or procedure, is complex and takes many twists and turns.

A cursory examination or reading of something is very quick, incomplete, and does not pay close attention to detail.

If you deliberate, you think about or discuss something very carefully, especially before making an important decision.

Didactic speech or writing is intended to teach something, especially a moral lesson.

Entropy is the lack of organization or measure of disorder currently in a system.

Someone who is erudite is steeped in knowledge because they have read and studied extensively.

Someone who is exacting expects others to work very hard and carefully.

Something that is extemporaneous, such as an action, speech, or performance, is done without any preparation or practice beforehand.

Someone who is fastidious cares excessively about small details and wants to keep everything correct, tidy, very clean, and in perfect order.

Something that is hypothetical is based on possible situations or events rather than actual ones.

If someone is impassive, they are not showing any emotion.

Someone is considered meticulous when they act with careful attention to detail.

A niggling feeling is slight and not really serious but irritates or bothers you over a long period of time.

Someone who is nonchalant is very relaxed and appears not to be worried about anything.

Something that is notional exists only as an idea or in theory—not in reality.

If you are oblivious to something that is happening, you do not notice it.

If you peruse some written text, you read it over carefully.

To be punctilious is to pay precise attention to detail.

A scrupulous person takes great care to do everything in an extremely honest, conscientious, and fair manner.

Someone who is sedulous works hard and performs tasks very carefully and thoroughly, not stopping their work until it is completely accomplished.

A spartan lifestyle is very simple and severe; it has no luxuries or comforts.

To act in an uncouth manner is to be awkward and unmannerly.

An unkempt person or thing is untidy and has not been kept neat.

If you repeat something verbatim, you use the same words that were spoken or written.

If something—such as power, influence, or feeling—wanes, it gradually becomes weaker or less important, often so much so that it eventually disappears.

A whimsical idea or person is slightly strange, unusual, and amusing rather than serious and practical.

A yokel is uneducated, naive, and unsophisticated; they do not know much about modern life or ideas because they sequester themselves in a rural setting.