hap (n.) Look up hap at Dictionary.com
c. 1200, "chance, a person's luck, fortune, fate;" also "unforeseen occurrence," from Old Norse happ "chance, good luck," from Proto-Germanic *hap- (source of Old English gehæp "convenient, fit"), from PIE *kob- "to suit, fit, succeed" (cognates: Old Church Slavonic kobu "fate, foreboding, omen," Old Irish cob "victory"). Meaning "good fortune" in English is from early 13c. Old Norse seems to have had the word only in positive senses.
hap (v.) Look up hap at Dictionary.com
"to come to pass, be the case," c. 1300, from hap (n.) "chance, fortune, luck, fate," or from Old English hæppan.