1. Vocabulary 13B

2. Implacable (adj.) not to be satisfied or pacified; unyielding
S: relentless, inexorable, unappeasable
A: lenient, indulgent, permissive, flexible
The peoples of the Arctic have shown that nature need not be an implacable foe.

3. Infinitesimal (adj.) so small as to be almost immeasurable; minute
S: tiny, minuscule, microscopic, unnoticeable
A: vast, immense, huge, infinite
To a fussy housekeeper, even an infinitesimal amount of dust on a tabletop is unacceptable.

4. Innocuous (adj.) harmless, inoffensive; insignificant
S: feeble, impotent, unobjectionable, insipid
A: harmful, dangerous, pernicious, toxic, virulent
Conversation at a dinner party may sometimes be confined to pleasant and innocuous generalities.

5. Militate
(v.) to have effect or force on or against someone or something, fight against
S: counter, oppose, work against
Health concerns militate strongly against the habitual use of tobacco and alcohol.

6. Patent
(n.) exclusive rights over an invention; copyright; (v.) to arrange or obtain such rights; (adj.) plan, open to view; copyrighted
S: (n.) exclusive, license; (adj.) evident
A: (adj.) concealed, hidden, secret, clandestine
When the patent on a drug expires, any manufacturer may produce it.
By the time of his death in 1931, Thomas Alva Edison had patented more inventions than any other American of his time.
During cross-examination a skilled lawyer may catch a key hostile witness in a patent falsehood.

7. Prowess (n.) distinguished bravery; superior skill or ability
S: valor, courage, heroism, mastery, proficiency
A: cowardice, incompetence, ineptitude
The Greek hero Achilles won fame for his prowess in the Trojan War.

8. Sedate (adj.) quiet, settled, sober; (v.) to administer a tranquilizer
S: (adj.) unruffled, composed, cool and collected
A: (adj.) loud, brash, flashy, flamboyant, garish, flighty
At concerts of classical music, audiences generally behave in a sedate and attentive manner.
A doctor may decide to sedate a patient who has suffered a severe emotional shock or physical injury.

9. Stentorian (adj.) extremely loud
S: thundering, booming, deafening, earsplitting
A: hushed, inaudible, whispered, mute
Some public speakers favor a stentorian delivery and emphatic gestures to drive home their message to their listeners.

10. Stipulate
(v.) to arrange specifically; to require as a condition of agreement
S: specify, contract, provide for
A financial institution may stipulate that all its employees be fingerprinted.

11. Ultimatum (n.) a final proposal or statement of conditions
S: final terms
As a strike deadline draws near, both labor and management can be expected to issue ultimatums.