Webster's Revised Unabridged Dictionary · 1913

Intervene

Intervene , intransitive verb

[Latin intervenire, interventum, to intervene, to hinder; inter between + venire to come; akin to English come: compare French intervenir. See Come.]

1.
To come between, or to be between, persons or things; -- followed by between; as, the Mediterranean intervenes between Europe and Africa.
2.
To occur, fall, or come between, points of time, or events; as, an instant intervened between the flash and the report; nothing intervened ( i. e., between the intention and the execution) to prevent the undertaking.
3.
To interpose; as, to intervene to settle a quarrel.
4.
In a suit to which one has not been made a party, to put forward a defense of one's interest in the subject matter. — Abbott

Intervene , transitive verb

To come between. [Rare]
Self-sown woodlands of birch, alder, etc., intervening the different estates. — De Quincey

Intervene , noun

A coming between; intervention; meeting. [Obsolete] — Sir H. Wotton