He behaved rather bumptiously and offended the hostess.
他太傲慢以至于冒犯了女主人。
bumptiously:冒失地, 自以为是地, 狂妄地 (副)
bumptious 瞎自夸的, 傲慢的, 瞎自大的 (形) | bumptiously 冒失地, 自以为是地, 狂妄地 (副) | bumpy 颠簸的; 崎岖不平的 (形)