Sentences:  “A darkling plain Swept with confused alarms of ____ and
flight.”  The ____ upon Fort Sumter was the direct cause of the Civil War. 
The ____ between our forces and theirs was brief and trivial; it was only
a cavalry ____.  There is an excellent account of a knightly ____ in
Ivanhoe.  We repelled their general ____; then ourselves advanced;
the ____ of our lines with theirs soon resulted in an inextricable ____. 
A chance ____ of small forces at Gettysburg brought on a terrible ____. 
There had long been ____ between the two factions within the party. 
Angered by what had begun as a playful ____, one of the men challenged the
other to ____.

Fleeting, transient, transitory, ephemeral, evanescent.

Sentences:  It is the lot of every one to endure many sorrows in
this ____ life.  They saw for a short while a[n] ____ comet.  The ____
glories of dawn had merged into the sordid realities of daytime.  The
remark made but a[n] ____ impression upon him.  The ____ moments sped away. 
“Art is long, and time is ____.”  Joy is ____.  Much of the popular
literature of the day is ____ in character.

Frank, candid, open, artless, guileless, ingenuous, unsophisticated, naive.

Sentences:  It was a[n] ____ excuse.  It was a pleasure to meet a
person so simple and ____.  He was ____ to say that he did not like the
arrangement.  “Who, mindful of the unhonored dead, Dost in these lines
their ____ tale relate.”  “The Moor is of a free and ____ nature.”  He gave
them his ____ opinion.

Frustrate, foil, thwart, counteract, circumvent, balk, baffle, outwit.

Sentences:  The schemers were themselves ____.  He was ____ by the
many contradictory clues.  Circumstances ____ all his plans to get rich. 
The parents ____ the attempt of the couple to elope.  The guard ____ the
prisoner’s attempt to escape.  He was ____ at every turn.  They put forth a
statement to ____ the influence of their opponents’ propaganda.  By
slipping away during the night, Washington ____ the enemy.  The politician
by his shrewdness ____ the attempt to discredit him.

Glad, happy, cheerful, mirthful, joyful, joyous, blithe, gay, frolicsome, merry, jolly, sportive, jovial, jocular, jocose, jocund.

Sentences:  “The milkmaid singeth ____.”  “And all went ____ as a
marriage bell.”  “How beautiful are the feet of them that preach the gospel
of peace, and bring ____ tidings of good things.”  A ____ Lothario.  “So
buxom, ____, and debonair.”  As ____ as a fawn.  He kept smiling, for he was
in ____ mood.  “You are sad Because you are not ____; and ’twere as easy
For you to laugh and leap, and say you are ____, Because you are not sad.” 
He longed for the ____ life of a ____ English squire.

Habit, custom, usage, practice, wont.