ascertainverb/ˌæsəˈteɪn/

• 1

  To find out definitely; to discover or establish.

  • As soon as we ascertain what the situation is, we can plan how to proceed.
  • “There the cause of death was soon ascertained ; the victim of this daring outrage had been stabbed to death from ear to ear with a long, sharp instrument, in shape like an antique stiletto, which […] was subsequently found under the cushions of the hansom.[…]”
• 2

  obsoleteTo make (someone) certain or confident about something; to inform.

  • Therfore the saide cõmissioners shall mowe say that nowe late during the parlement the King ascertaigned of the saide maliciouse pʳpose of his enemys, willed and desired the lords being then present to shewe their̃ good willes aide and helpe for the saide rescues[…]
  • We would most gladly ye came yourself if that ye may […] praying you to ascertain us of your News.
• 3

  datedTo look for something lost.

• 4

  archaicTo establish, to prove.

  • The two firſt lines of the following book ſeem to aſcertain the true meaning of the concluſion of this, and to prove ſufficiently that by Ωκεανός here, Homer could not poſſibly intend any other than a river.
  • In 1695 he [Walter Moyle] was chosen to represent the borough of Saltash in parliament ; a circumstance which ascertains the piece before us to have been written subsequent to that period.
• 5

  archaicTo ensure or effect.

  • It is true, that no diligence can aſcertain ſucceſs ; death may intercept the ſwifteſt career ; but he who is cut off in the execution of an honeſt undertaking, has at leaſt the honour of falling in his rank, and has fought the battle, though he miſſed the victory.
  • The ministry, in order to ascertain a majority in the house of lords, persuaded the queen to take a measure which nothing but necessity could justify.