a-sa' (ya'al; nacah; peirdzein; peirasthai; peiran lambanein): The Hebrew and Greek words which are rendered in the King James Version "assay" are so rendered in the Revised Version (British and American), and the use of it is extended in the Revised Version (British and American) in two additional cases. The Hebrew word ya'al (1Sa 17:39) is used of David clad in Saul's armor, who "assayed," that is, "tried unsuccessfully," to go and attack Goliath in it, for "he had not proved it," where nacah is the verb. In De 4:34 and Job 4:2 nacah is rendered "assay," in the sense of "attempt," "venture." In Ac 16:7 Paul is said to have "assayed," that is, "attempted" (but was hindered), to go into Bithynia, and now in Ac 24:6 Paul is charged with having "assayed," that is, "having had the audacity," to profane the temple, where peirazein is the verb used in both cases. In Ac 9:26, and now in the Revised Version (British and American) Ac 26:21, "assay," renders the verb peirasthai, "to attempt," in both cases unsuccessfully. In Heb 11:29 it translates two Greek words peiran lambanein "to make an attempt unsuccessfully."
⇒See the definition of assay in the KJV Dictionary