Language: Ottoman Turkish
Source: Antique object
Haci Gavsî is the name an Ottoman bowyer used to sign a bow made in late 1824 or 1825.
"Amel-i haci gavsî 1240"
Literally the signature says: “Made by Haci Gavsî 1240”
The year 1240 of the Islamic calendar in use at the time lasted from August 26, 1824 to July 18, 1825.
Haci is a title used by those who went to Mecca during one of two special periods; The ultimate goal of every Muslim. This title is normally followed by a person’s name, but in this case it may be a nickname: "kavs" or "gavs" is the Arabic word for “bow”.
It might translate as “The Pilgrim Bowyer”. I have not been able to find other mentions of this person.