1.Laggard

Meaning: a person who makes slow progress and falls behind others.

Synonym: straggler, loiterer, lingerer, dawdler

Sentence:”staff were under enormous pressure and there was no time for laggards”

2.Opulent

Meaning: ostentatiously costly and luxurious.

Synonym: luxurious, sumptuous, palatial

Antonym: penniless, poor, impoverished, penurious

Sentence: “the opulent comfort of a limousine”

3.Tautology

Meaning: the saying of the same thing twice over in different words, generally considered to be a fault of style 

Synonym: repetition, repetitiveness 

Sentence: When the lawyer spoke to the jury, he used tautology to make the jurors aware of his point without being repetitive.

4.Sinuous

Meaning: having many curves and turns.

Synonym: windy, serpentine, curving, twisting

Antonym: straight

Sentence: “the river follows a sinuous trail through the dale”

5.Altercation

Meaning:  a noisy argument or disagreement, especially in public.

Synonym: argument, quarrel, squabble, fight,

Sentence:”I had an altercation with the ticket collector”

6.Sentinel

Meaning: a soldier or guard whose job is to stand and keep watch.

Synonym: guard, keeper

Sentence: “soldiers stood sentinel with their muskets”

7.Repercussion

Meaning: an unintended consequence of an event or action, especially 

an unwelcome one.

Synonym: consequence, result, effect, outcome,

Sentence: “the move would have grave repercussions for the entire region”

8.Pristine

Meaning: in its original condition; unspoiled.

Synonym: immaculate, in perfect condition

Antonym: dirty, sullied

Sentence: “pristine copies of an early magazine”

9.Sporadic

Meaning: occurring at irregular intervals or only in a few places; scattered or isolated

Synonym: occasional, infrequent, irregular, periodical

Antonym: frequent, regular, steady, continuous

Sentence: “sporadic fighting broke out”

10.Soporific

Meaning: tending to induce drowsiness or sleep., a drug or other substance that induces drowsiness or sleep.

Synonym: sleeping pill, sleeping potion, sedative, calmative, tranquilizer, narcotic, opiate;

Antonym: invigorating,  stimulant

Sentence: “the motion of the train had a somewhat soporific effect”