When someone is fastidious, that person pays attention to details with great care. For instance, a "fastidious dresser" is someone who likely cleans, presses, and matches his or her clothes very well—down to the last detail. In contrast to such a personality, we can consider someone who is lax with such details. We would describe such a person as being "heedless." If we heed something, we pay attention to it. To be "heedless" is to give no such "heed"—i.e. attention—to matters.

The character trait "industry" means diligence. To be industrious is to be very careful and strenuous about the needs of work to be done. In contrast to this, the vice "sloth" indicates a kind of laziness and unwillingness to work. Someone who is "slothful" is quite the opposite of an "industrious" person.

The word "gregarious" comes from the Latin for a flock—as in a flock of animals. When we say that someone is gregarious, we mean to say that the person is friendly—capable of being in the "flock" of other people. In contrast to this, an "aloof" person is distant and not very friendly.

If someone is "ostentatious" he or she is very showy—to the point of being quite uncultured in appearance. This generally is done in order to be appreciated and noticed by others. In contrast to this, someone who is "sober" does not merely avoid alcohol (as we often use the word "sober") but above all is very serious and understated in his or her demeanor.

Do not be fooled by the options that all start with "sub-" or "sup-." Although "sub-" is a prefix meaning under, this does not necessarily mean that it should provide the clue for all antonyms beginning with "super-," which means over or above. A supercilious person always looks down on others, as though he or she is better than them. Such a person is arrogant and likely forceful and/or bossy. In contrast to such a person, a meek person is gentle and submissive. This is the best option for an antonym among those given.

The word "loquacious" comes from a rich family of words related to the Latin root for to talk. Such related words are "colloquy," "eloquent," "locution," and "grandiloquent." To be "loquacious" is to be talkative. In contrast to this, a person who is "taciturn" is quiet, speaking few words. A "tacit" agreement is one that is assumed without anything being said explicitly. The words "prolix" and "voluble" are both relatively good synonyms for "loquacious."

The word "cerebral" means intellectual or logical. The opposite of logical is "emotional". "Intelligent" is a synonym of cerebral. "Indigent" means poor and "pompous" means that you feel superior to someone. 

If a person is "pompous," he or she is self-important or overbearing. You might say, "The student body president was overly pompous when she insisted on constantly correcting other officers during the meeting." Someone who is NOT pompous could be said to be "modest," or humble.