Vocabulary - 1

(2) Notorious is infamous; others are deceitful.

Intractable means difficult to manage, control, or influence. Its antonym is manageable, which describes something easily handled or controlled. The other options (offensive, nautical, spruce) are not opposite in meaning.

Kindle means to ignite or set fire to. Its antonym is extinguish, which means to put out fire or light. Ignore is not the true opposite. Kindle can also mean to arouse or inspire, but extinguish remains the best antonym.

Shallow means not deep, lacking depth. Its antonym is deep, which is the direct opposite. Hollow means having a space or cavity inside, which is different from depth. High refers to height, not depth.

Lethal means deadly, fatal, or causing death. Deadly is the closest synonym. Unlawful means illegal, sluggish means slow or lacking energy, and smooth means even or lacking roughness - none of these relate to causing death.

To deify someone or something is to impart the status of godhood, i.e. making a person god. Hence, worship is synonymous because when we worship someone, such as a hero, we are imparting a godlike status upon him.

Serene is synonymous with calm.

Advance is opposite in meaning to recede. 

Union

Gruesome means causing great horror. So, option 4 is the correct synonym.

Placid means calm and peaceful.