The most common and most likely answer to this crossword clue is the 5 letter word OVARY
I've seen this crossword clue in Financial Times
O
V
A
R
Y
More clues leading to the result OVARY
- No change in gland
- Organ and piano ultimately are not the same
- Initially observe change in gland
- Flaubert’s Emma goes topless for female part
- Madame loses her head for egg producer
- Head of ordering to change supplier of eggs
- Literary heroine book cast in vital female part
- Row about very variable organ
- Males don’t have it? Nothing to disagree
- After goose egg, change egg source
Buddy explains!

The straight part
We know that "female par" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case female par = ovary.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does OVARY mean?
OVARY noun- A female reproductive organ, often paired, that produces ova and in mammals secretes the hormones estrogen and progesterone.
- The lower part of a pistil or carpel that bears ovules and ripens into fruit.