It’s vulgar, and yes the english word to translate it could be « pussy »

Per the description; it’s tagged for a men acting like a women

Fig. Homme qui a des manières féminines. C’est une vraie > femmelette, comment supportera-t-il les fatigues de la > guerre s’il est appelé à l’armée ?

In Canadian French it’s not much used. « Feluette » is more used or even « tapette » which is more vulgar.

• Feluette is a derivate word from fluet.

The urban dictionnary description:

feluette similar to “moumoune”, meaning wuss or weakling. Force un
peu, maudite feluette!

• tapette is more vulgar, as the primary meaning is a vulgar word that mean a homosexual, but it can be used to taunt someone else like feluette or femmelette.

In a conversation these words can be used for taunting (« narguer »), so the usage meaning can vary on the situation, but it’s still vulgar in any case.

Femmelette is offensive because it’s an insult in two parts. The -lette suffix is a diminutive, saying that the person is less than a femme. And it builds on femme (i.e. “woman”), saying that the person is inferior for being a woman.

If femmelette was the feminine version of *hommelet, it would merely be an insult. But *hommelet* doesn’t exist. Using femmelette is intrinsically sexist.

(My perspective is from France. Some dialects may use the word more or less, but the offensiveness is cross-dialectal.)