fear (n.) Look up fear at Dictionary.com
Old English fær "calamity, sudden danger, peril," from Proto-Germanic *feraz "danger" (cognates: Old Saxon far "ambush," Old Norse far "harm, distress, deception," Dutch gevaar, German Gefahr "danger"), from PIE verbal root *per- (3) "to try, risk" (source also of Greek peira "trial, attempt, experience," Latin periculum "trial, risk, danger"), related to *per- (1) "forward, through" (see per).

Sense of "uneasiness caused by possible danger" developed late 12c. Old English words for "fear" as we now use it were ege, fyrhto; as a verb, ondrædan.
fear (v.) Look up fear at Dictionary.com
Old English færan "terrify, frighten," originally transitive (sense preserved in archaic I fear me and somewhat revived in digital gaming). Meaning "feel fear" is late 14c. Cognate with Old Saxon faron "to lie in wait," Middle Dutch vaeren "to fear," Old High German faren "to plot against," Old Norse færa "to taunt." See fear (n.). Related: Feared; fearing.