: something that has or can have both favorable and unfavorable consequences
Is the definition above correct for the phrase 'double-edged sword'?
Please give a few examples to help me understand it better? Thanks in advance
Yes, it can help you as well as hurt you. The related expression is "It cuts both ways."
Sometimes it's called a two-edged sword.
Yes, it's rigth. You can also use 'double-edged weapon'.
For example, sitting in front of a PC is a double-edged sword: you can obtain a lot of knowledge (a positive consequence), but you can also spoil your eyesight (a negative consequence).