The term "perfect" has several different uses, some stemming from its original meaning (complete, absolute) and some from the more recent development of its evaluative aspect (faultless, most excellent):
* For the mathematical concept see perfect number.
* In formal methods of computing, see Perfect Developer.
* For the philosophical concept see perfection (concept).
* For the grammatical concept see perfect aspect.
* For the legal concept see perfection (law).
* In botany and mycology, an organism is considered perfect if it is capable of sexual reproduction; otherwise it is imperfect.
**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" (or ''synoecious'') if it has both male and female reproductive parts. A perfect or hermaphroditic flower has both stamens and an ovary. If a flower has just male or just female parts it is termed "imperfect".
* In music:
** Perfect intervals include the perfect octave, perfect fifth, perfect fourth, and perfect unison.
** Perfect (John Cale song)