eyewitnessing1
/ˈʌɪˌwɪtnɪsɪŋ/noun
The action or an act of eyewitnessing something; observation with one's own eyes.
Origin
Mid 17th century. From eyewitness + -ing.
eyewitnessing2
/ˈʌɪˌwɪtnɪsɪŋ/adjective
That observes or describes an incident or event as an eyewitness. In early use also: †that bears witness to something (obsolete ).
Origin
Early 17th century; earliest use found in William Lithgow (1582–c1645), traveller. From eyewitness + -ing.