- reference
- 1589, "act of referring," from refer (q.v.). Meaning "direction to a book or passage" is recorded from 1612. Meaning "testimonial" is from 1895. The verb first is attested 1884. Reference book dates from 1889 (earlier book of reference, 1836). Phrase in reference to is attested from 1594. Referential is attested from 1660.