speculation in WordNet English dictionary

1. a hypothesis that has been formed by speculating or conjecturing (usually with little hard evidence)
   "speculations about the outcome of the election"; "he dismissed it as mere conjecture"
   speculation  conjecture 
   
2. a message expressing an opinion based on incomplete evidence
   guess  conjecture  supposition  surmise  surmisal  speculation  hypothesis 
   
3. continuous and profound contemplation or musing on a subject or series of subjects of a deep or abstruse nature
   "the habit of meditation is the basis for all real knowledge"
   meditation  speculation 
   
4. an investment that is very risky but could yield great profits
   "he knew the stock was a speculation when he bought it"
   speculation  venture