Literally: blind/reckless – word – many – apology
Alternately: This is a utilitarian phrase used to ask forgiveness after speaking in an imprudent, careless, or prejudiced way. For example, it may be found at the end of a personal letter, especially one in which the writer openly expressed a potentially problematic emotion or opinion, instead of wrapping it in tactful niceties.
Notes: 妄 may, rarely, be pronounced bou. However, it cannot be replaced with homophone 盲, even though it can also mean “blind.”