In botany and mycology, an organism is considered perfect if it is capable of sexual reproduction; otherwise it is imperfect. The terms have nothing to do with the quality of an organism.
Fungi in the Division Deuteromycota (informally called the Fungi imperfecti) are so classified because sexual reproduction is unknown (or may not occur) in these species.
A flower is called perfect (synoecious) if it has both male and female reproductive parts. A perfect or bisexual flower has both stamens and an ovary. If a flower has just male or just female parts it is termed imperfect.