Something that is "lulling" is soothing. A "lull" is a quiet time. For instance, at a restaurant, there can be a "lull" when patrons stop coming—giving the workers a quiet time to recover. Now, a "lulling" voice can put someone to sleep, but this does not mean that something that is "lulling" is itself sleepy. The basic synonym for "lull" that works best is just the simple word "soothing."

"Robust" is an adjective meaning hearty or powerful. For example: "The extremely spicy ingredients caused the sauce to have a ROBUST taste and aroma."

"Fragile" is an antonym to "robust." "Rotund" is an adjective describing an object with a round shape or a corpulent person. "Belligerent" is an adjective used to describe a person who is aggressive or unpleasant.

"Rigorous" is an adjective describing something very difficult, thorough, or demanding. For example: "The RIGOROUS course of study caused many students to either fail or quit."

"Talentless" is an adjective used to describe someone who is without skill at a given task. "Straight" is a concrete adjective using to describe a specific, linear directionality of a movement or the shape or arrangement of an object or objects. 

An "abrasive" is something scratchy and is usually used to help smooth an object or clean something. Sandpaper is abrasive as are the scratchy sides of sponges used to clean dishes. "Smooth" is an antonym to "abrasive." "Clean" means free of dirt. "Sticky" is an adjective describing a gummy or adhesive texture. "Ugly" is an adjective describing an unsightly person or object.

"Surgical" means precise, accurate. If you think about the fact that a "surgeon" needs to be precise and accurate to do their job this makes a lot of sense. 

"Mean" can have many different meanings, but when used as an adjective in a mathematical or statistical sense it means average. To provide further help, "forthright" means honest; "supreme" means best, greatest; "polarizing" means divisive, causing radically different opinions; "abundant" means existing in large quantities.

"Petty" means trivial, minor, insignificant. To provide further help, "incredible" means amazing and "unbelievable" means not believable. Interestingly "credible" means "believable." Here we can see how words change and evolve over time, when once "incredible" meant simply not believable, now it means something closer to amazing because it is barely believable. Additionally, "indelible" means a mark that cannot be removed; "untimely" means happening at the wrong time, happening too soon. 

Something that is described as "shoddy" is poorly made, of inferior quality. "Inferior" means not as good as, worse. To provide further help, "superior" means better than; "mediocre" means average in a bad way; "exemplary" means perfect, flawless, a perfect example of. 

"Sophisticated" is an adjective that can be used to describe either machinery, technology, or people. It means advanced, modern, not crude. To provide further help, "crude" means basic, lacking detail and sophistication; "unusual" means not normal; "standard" means normal, common; "intermediate" means middle, mid-way, transitional.

Whenever something is "exemplary," it is excellent. Indeed, the word itself can help us understand its meaning. An "exemplary" thing sets a very good example in some particular way. Thus, such a thing or person provides an "ideal." For example, an exemplary student is someone who is an ideal student whom others should imitate.