voluntary; optional; free; elective
cross-examination; close questioning; demanding an explanation
to probe; to search; to sound out; to investigate
black curtain; wirepuller; mastermind; backroom manipulator
outline; summary; overview; synopsis; abstract; abridgment
difference; disagreement; conflict; clash; discrepancy; inconsistency
stepping (in place); stamping (up and down); stomping; standstill; stalemate
great disaster; horrible tragedy; catastrophe; catastrophic event; catastrophic incident; dire calamity
starting point; origin; origin (of coordinate axes); datum point
husband and wife; married couple
to crowd (a house); to throng to (a door)
later on; eventually; afterwards
bow-wow; woof; wah-wah; bawling; clamouring; clamoring
licking; lapping up; (eating up) quickly; gobbling up
hound; hunting dog; gun dog
resigning to another's will; going along without resistance; doing as another wants
Nichole; Nicholl; Nicol; Nicoll; Nicolle
rug; lag (esp. in online gaming)
way of asking; way of listening; listener
blushing; getting red in the face; embarrassment
rambunctious kid; wild kid; hooligan; rowdy; roughneck
incomplete combustion; imperfect combustion; being off one's game; not doing one's best; being unable to use all of one's strength
one large animal (horses, cattle, etc.); head (of cattle)
desirable; hoped for; preferable; advisable
running as fast as one can
waste of time; killing time
stupid; meaningless; worthless; hopeless (person, situation); beyond help; beyond saving
obedient; gentle; meek; submissive; docile
well-behaved (esp. children and pets); obedient; good
toppling sideways; turning sideways; falling over sideways; barrel roll
order; command; directions; instructions
master and servant; lord and retainer; employer and employee
being stuck between a rock and a hard place; being in a dilemma; being torn between conflicting demands
to exterminate; to eliminate; to eradicate; to suppress