timorous

那只小狗见到陌生人时表现得很胆怯。

The little dog was ___timorous when it saw strangers.

她在董事会演讲时怯生生的低语几乎被空调的嗡嗡声完全淹没。

Her ___timorous whisper was almost swallowed by the hum of the air conditioner during the board presentation.

他怯生生地踏上了玻璃桥，手指紧扣栏杆发白。

He took a ___timorous step onto the glass-bottomed bridge, his knuckles white as he gripped the railing.