This is the 8296th most frequent Japanese word.
弱き
"Weakness" or "the weak."
Here, '弱き者' refers to 'the weak ones' or 'people who are vulnerable'. The term '弱き' is used as an adjective to describe '者' (persons).
弱き者を助けるのは大切なことです。
Helping the weak is important.
In this sentence, '弱き' is used as an adjective to describe '雨' (rain), meaning 'weak' or 'light rain'.
この花は弱き雨に打たれて散った。
This flower was scattered under the weak rain.
Here, the phrase '弱き時' means 'moments of weakness', where '弱き' functions as an adjective describing '時' (moments).