Verb

(es)

To declare freely and openly; to assert.

* Shakespeare

if this which he avouches does appear

* Spenser

Such antiquities could have been avouched for the Irish.

To acknowledge deliberately; to admit; to confess; to sanction.

* Bible, Deuteronomy xxvi. 17

Thou hast avouched the Lord this day to be thy God.

To confirm or verify, to affirm the validity of.

* Milman

We might be disposed to question its authenticity, it if were not avouched by the full evidence.

To appeal to; to cite or claim as authority.

* Edward Coke

They avouch many successions of authorities.

Verb

(en verb)

(obsolete) To support (someone), to back up or assist (someone) in an action.

*:

*:And thenne he asked leue & wente oute of his heremytage for to mayntene his neuewe ageynst the myghty Erle / and so hit happed that this man that lyeth here dede dyd so moche by his wysedome and hardynes that the Erle was take and thre of his lordes by force of this dede man

To keep up; to preserve; to uphold (a state, condition etc.).

*, chapter=17

, title= The Mirror and the Lamp , passage=This time was most dreadful for Lilian. Thrown on her own resources and almost penniless, she maintained herself and paid the rent of a wretched room near the hospital by working as a charwoman, sempstress, anything. In a moment she had dropped to the level of a casual labourer.}}

*{{quote-news, year=2011, date=November 5, author=Phil Dawkes, work=BBC Sport

, title= QPR 2-3 Man City , passage=Mancini's men were far from their best but dug in to earn a 10th win in 11 league games and an eighth successive victory in all competitions to maintain their five-point lead at the top of the table.}}

*{{quote-magazine, date=2013-03, author=Nancy Langston, volume=101, issue=2, page=98

, magazine=(American Scientist) , title= Mining the Boreal North , passage=Reindeer are well suited to the taiga’s frigid winters. They can maintain a thermogradient between body core and the environment of up to 100 degrees, in part because of insulation provided by their fur, and in part because of counter-current vascular heat exchange systems in their legs and nasal passages.}}

To declare or affirm (a clause) to be true; to assert.

* {{quote-news, year=2012, date=April 19, author=Josh Halliday, work=the Guardian

, title= Free speech haven or lawless cesspool – can the internet be civilised? , passage=She maintains that the internet should face similar curbs to TV because young people are increasingly living online. "It's totally different, someone at Google watching the video from the comfort of their office in San Francisco to someone from a council house in London, where this video is happening right outside their front door."}}