1 adjectives to describe apprehensiveness

You remember, no doubt, that an envious but keen-eyed classmate observed that the smart speller worked off his nervous apprehensiveness by twirling the top button of his coat as he correctly spelled word after word, day in and day out; and how the keen-eyed one played the part of a stealthy villain and surreptitiously cut the button off the coat.

1 adjectives to describe  apprehensiveness