Nouns in the English language do not have genders, unlike French and German, for example. Therefore the noun 'picnic' does not have a gender, so it cannot have an opposite gender.
Picnics are usually fun, relaxing and enjoyable. so, the phrase 'its no picnic' means the opposite. it may be hard, stressful, and unenjoyable. the opposite of a picnic.
Doctor is a neuter gender
Opposite gender of Filipino: Filipina
Clot is not gender specific.
Opposite gender of a Filipino: FILIPINA
There isn't an opposite gender of farmer. A farmer can be either a male or a female.
An emperor is the opposite in gender to an empress.
The opposite gender for Joseph is Josephine.
The opposite gender of giantess is giant.
The opposite of dairymaid is dairyman.
gentlewoman....
Mistress is the opposite gender of master.