What is the meaning of [Frailty, thy name is woman]

Alluding to the alleged inherent weakness of character of women.

From Shakespeare’s Hamlet, 1602:

Must I remember? why, she would hang on him,
As if increase of appetite had grown
By what it fed on: and yet, within a month –
Let me not think on’t – Frailty, thy name is woman! –
A little month, or ere those shoes were old
With which she follow’d my poor father’s body…