This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 犮 is uncertain. It appears as a component in other characters, but its independent origin is unclear.
Since the meaning is unclear, focus on the shape: it looks like a dog (犬) with an extra mark, or a person (大) with something added. Remember it as a rare, obscure character.
For ハツ, imagine a rare, obscure character named Hatsu who looks like a dog with a hat: Hatsu -> ハツ, and the hat is the extra stroke on top of 犬.