Definition of "could"

simple past of can  examples

conditional of can

1. Used as a past subjunctive (contrary to fact).  examples

2. Used to politely ask for permission to do something.  examples

3. Used to politely ask for someone else to do something.  examples

4. Used to show the possibility that something might happen.  quotations  examples

   Quotations

   • Even without hovering drones, a lurking assassin, a thumping score and a denouement, the real-life story of Edward Snowden, a rogue spy on the run, could be straight out of the cinema. But, as with Hollywood, the subplots and exotic locations may distract from the real message: America’s discomfort and its foes’ glee.

     2013 June 29, “Travels and travails”, in The Economist, volume 407, number 8842, page 55

5. Used to suggest something.  examples

(obsolete except Tyneside) past participle of can  quotations

Something that could happen, or could be the case, under different circumstances; a potentiality.  quotations  examples