けたたましい (translations)→ clamour frenzied piercing sharp shrill urgently wailing
ときならぬ (translations)→ early unusual
はからずも (translations)→ happen incidentally involuntarily
ふとした (translations)→ odd passing trifling
案外 (translations)→ but maybe possibly rather really strangely surprise surprisingly
意外な (translations)→ astonished expect extraordinary obvious surprised
奇想天外な (translations)→ crazy egregious fantastic Pythonesque zany
思いがけない (translations)→ abrupt accidental alarming curious disproportionately piece startle strange unbelievable unheralded unsuspected
思いがけなく (translations)→ stumble uncharacteristic
思いがけぬ (translations)→ bonus unfamiliar unforeseen
突拍子もない (translations)→ absurd extravagant insane mad outlandish outrageous preposterous quixotic remote wild
不意の (translations)→ emergent unscheduled
不測の (translations)→ unguessed unpredictable
