The lofty standing of "20/20" surely has something to do with ABC's persistent inability to find any success in the hourlong entertainment format.

A man who has some history of normal erections during intercourse, but has developed a persistent inability to obtain or maintain erections, has secondary erectile dysfunction.

In its patent, the inventors define female sexual arousal disorder as the persistent or recurrent inability to attain, or to maintain, sufficient sexual excitement, which causes personal distress.

Mr. Giuliani's persistent inability to accept the Constitution leaves little doubt of which road (the low one) he plans to take to the United States Senate.

Sometimes the very strongest of our variety of Gifts hide themselves; I've known a case or two when persistent inability has actually hidden very strong ability.

Instead, a persistent inability to make his teams aggressive, fearless and efficient in the usually welcoming atmosphere of prosperity did him in.

And that only made him more ashamed of his own persistent inability to rise above his feelings and be the sort of executive officer she deserved for him to be.

The umpires are counting on judgment errors and a persistent inability to control the games by their replacements to advance a settlement.

He performed poorly on exams which he attributes to his persistent inability to commit facts to memory.

Cabaret's persistent inability to provide her with financial security would surprise at least one person, Ms. Cary maintains.