This is the 6770th most frequent Spanish word.
cosi
"Cosi" is not a standard Spanish word. It may be a typo or slang.
The word 'cosí' here is the past form of the verb 'coser,' meaning 'I sewed.'
Cosí el botón en su camisa con cuidado.
I sewed the button on his shirt carefully.
The word 'cosí' is used to indicate past action of sewing in first person.
Entonces, cosí los retazos de tela para formar una manta.
So, I sewed the fabric scraps together to make a blanket.
In this case, there is a mistaken usage of 'cosí' from someone trying to use 'así que' (so) in an exploratory manner, possibly a typo or intentional error for expression.