ascertain
ascertain (ăsər-tānʹ) verb, transitive
ascertained, ascertaining, ascertains
1. To discover with certainty, as through examination or experimentation. See synonyms at discover.
2. Archaic. To make certain, definite, and precise.
[Middle English acertainen, to inform, from Old French acertener, ascertain- : a-, to (from Latin ad-). See ad- + certain, certain. See certain.]
ascertainʹable adjective
ascertainʹableness noun
ascertainʹably adverb
ascertainʹment noun