English word fortear comes from English tear, English for-

Detailed word origin of fortear

Dictionary entry	Language	Definition
tear	English (eng)	(intransitive) To become torn, especially accidentally.. (intransitive) To move or act with great speed, energy, or violence.. (intransitive) To smash or enter something with great force.. (transitive) To destroy or reduce abstract unity or coherence, such as social, political or emotional.. (transitive) To injure as if by pulling apart.. (transitive) To make (an opening) with force or [...]
for-	English (eng)	(dialectal) Very; excessively.. (no longer productive) Meaning "completely", "to the fullest extent" e.g. forbreak; superseded by combinations with "up" in senses where no upward movement is involved, e.g. forgive = give up (one's offenses), forgather = "gather up", forbeat = "beat up", etc.. (no longer productive) Meaning "far", "away"; "from", "out" e.g. forbid, forget, forsay; forbear, fordeem.
fortear	English (eng)	(transitive) To tear up; tear to pieces.

Words with the same origin as fortear