WordNet sense 1 (fail to do something; leave something undone):

neglect

WordNet sense 2 (be unsuccessful):

miscarry, go wrong

WordNet sense 3 (fail to get a passing grade):

bomb, flunk, flush it

WordNet sense 4 (disappoint, prove undependable to; abandon, forsake):

betray

WordNet sense 5 (prove insufficient):

run out, give out

WordNet sense 6 (stop operating or functioning):

break, die, go, break down, give way, conk out, go bad