Tenuous

Tenuous-adjective
1-not based on anything significant or substantial, and so liable to break down easily when challenged
2-thin and fine and so easily broken (literary)
3-thin or diluted in consistency

Synonyms
weak
feeble
half hearted
shaky
vague
unsubstantiated
fragile
unconvincing
questionable
strong (antonym)

Solicitous

Solicitous-adjective
1-expressing an attitude of concern and consideration
2-full of eagerness and anticipation to do something
3-paying very careful attention to details
4-troubled by uneasiness or apprehension (archaic)

Synonyms
considerate
caring
attentive
concerned
kind
uncaring (antonym)

Shrewd

Shrewd-adjective
1-showing or possessing intelligence, insight, and sound judgment, especially in business or politics
2-based on good judgment and probably correct
3-inclined to deal with others in a clever, underhanded way
4-piercing or sharp (archaic)

Synonyms
astute
perceptive
cunning
sharp
insightful
sharp-witted
on the ball
wise
canny
smart
clever
naive (antonym)

Benign

Benign-adjective
1-having a kind and gentle disposition or appearance
2-not a threat to life or long-term health, especially by being noncancerous
3-neutral or harmless in its effect or influence
4-mild or favorable in effect

Synonyms
kind
benevolent
kindly
gentle
compassionate
malignant (antonym)

Missive

Missive-noun
a letter or written communication

Synonyms
letter
communique
note
communication
memo
memorandum
notification

Rife

Rife-adjective
1-occuring everywhere in plentiful supply
2-full of or severely affected by something undesirable

Synonyms
widespread
common
andemic
extensive
prevalent
ubiquitous
dredominant
rampant
sparse (antonym)

Beseech

Beseech-vt (literary)
1-to ask ernestly or beg somebody to do something
2-to ask urgently for something

Synonyms
implore
beg
request
ask
entreat
plead
press
demand