backfriend

A friend who supports someone; a person who has someone's back; a backer, a supporter.

They had vvings of goodvvill to fly vvith, but no vvebbes on their feete to ſvvimme vvith, for except the vvaterfoules had mercie vpon them, and ſtood their faithfull confederates and backe-friends, on their backes to tranſport them, they might returne home like good fooles, and gather ſtravves to build their neſts, or fal to theyr old trade of picking vvormes.

Tho they give us neither VVine nor Ale; yet if they give us a Cup of cold VVater in the time of need, in the name of Diſciple, in the name of Miniſters, they ſhall not loſe their Revvard. Novv, vvell's us for our Back-friend, he vvill ay maintain our Cauſe; […]

Synonym of hangnail (“a loose, narrow strip of nail tissue protruding from the side edge and anchored near the base of a fingernail or toenail”).

[…] Corrie bit another atom from off the corner of his nail. He had a troublesome "back-friend" or "agnail," at which he often bit.

A person who pretends to be someone's friend; a false friend, a secret enemy.

A Feind, a Fairie, pittileſſe and ruffe: / A VVolfe, nay vvorſe, a fellovv all in buffe: / A back friend, a ſhoulder-clapper, one that countermãds / The paſſages of allies, creekes, and narrovv lands: […]

[…] VVeſtmorland thought it ſafeſt to checke the Scots, as the neerer and continuall backe-friends.