the word 'succor' entered english in the 13th century from old french succur(s), meaning 'aid, help, relief'. the old french term derived from medieval latin succursus, a noun formed from the past participle of latin succurrere, meaning 'to run to the aid of, to help'. this latin verb is a compound of sub- (meaning 'from below, up to') and currere (meaning 'to run'). the literal image is of running to someone's assistance. the spelling was later influenced by latin to include the 'c', though the 'succor' form has been standard in american english, while 'succour' is common in british english. the core concept has remained consistent from its latin roots: the act of rushing to provide relief in times of distress.

this word is a loanword from old french, where its form was already tightly fused. it is not productively formed from separable english morphemes.