[fail] vb [ME failen, fr. OF faillir, fr. (assumed) VL fallire, alter. of L fallere to deceive, disappoint] vi (13c) 1 a: to lose strength: weaken "her health was ~ing" b: to fade or die away "until our family line ~s" c: to stop functioning "the patient's heart ~ed"
2. a: to fall short "~ed in his duty" b: to be or become absent or inadequate "the water supply ~ed" c: to be unsuccessful (as in passing an examination) d: to become bankrupt or insolvent ~ vt 1 a: to disappoint the expectations or trust of "her friends ~ed her" b: to miss performing an expected service or function for "his wit ~ed him"
2: to be deficient in: lack "never ~ed an invincible courage --Douglas MacArthur"
3: to leave undone: neglect "~ to lock the door"
4. a: to be unsuccessful in passing (as a test) b: to grade (as a student) as not passing -- fail.ing.ly adv
[2]fail n (13c) 1: failure--usu. used in the phrase without fail
2: a failure (as by a security dealer) to deliver or receive securities within a prescribed period after purchase or sale