Vocabulary

1. LOCUS (noun)
Meaning: a particular position or place where something occurs or is situated
Synonyms: arrangement, location, condition, circumstances
Antonyms: boon, disarrangement
Example: The locus of these intersections is the quadratrix.

2. DISCORD (noun)
Meaning: disagreement between people.
Synonyms: strife, conflict, friction, hostility
Antonyms: agreement, accord, harmony
Example: A note of discord has crept into relations between the two countries.

3. INVASIVE (adjective)
Meaning: tending to spread very quickly and undesirably or harmfully.
Synonyms: nosy, interfering
Example: The samples tested in this series may not include a high proportion of health care staff involved in invasive procedures.

4. OMINOUS (adjective)
Meaning: giving the worrying impression that something bad is going to happen; threateningly inauspicious.
Synonyms: threatening, menacing, baleful, forbidding
Antonyms: promising, auspicious, propitious
Example: There were ominous dark clouds gathering overhead.

5. VITIATE (verb)
Meaning: spoil or impair the quality or efficiency of.
Synonyms: annihilate, negate, quash, abate
Antonyms: allow, help, permit, affirm
Example: Changes at this point may actually vitiate the entire system.