vagary

"Outdoor events are always risky due to the vagaries of the weather. "

"The teacher handed out a schedule for the week's activities. "

"The large, out-of-place granite rock in the farmer's field was clearly an erratic, deposited there long ago by a retreating glacier. "

"the old reliables"

"The traffic is slow during rush hour."

"The sudden opportunity was the impulsive behind her decision to quit her job and travel the world. "

"I received an illogical reply and that left me standing there feeling confused."

"He regretted his words."

"The students are subject to strict rules about late arrivals. "

"The frequent occurrence of noisy construction near my house has made it hard to concentrate on my studies. "

"The weather today is an unpredictable. "

"After careful consideration, the student made a decision about which college to attend. "