1. chattering (teeth)
Adjective (な)
Onomatopoeic
2. (frozen, worried) stiff
Adjective (な)
Adjective (の)
Onomatopoeic
3. rigid (personality, thinking, etc.); inflexible; overly serious
Adverb
Adjective (の)
Onomatopoeic
4. voracious (e.g. work, study); without slack or pause