Imamzadeh means "offspring" or descendent of an imam. There are many other different ways of spelling this term. Some of these are imamzada, imamzadah, and emamzadah. These all have the same meanings. Imamzadeh are basically the Syed's or Syeda's as they have descended from the Imams.
Imamzadeh is also a term for a shrine-tomb of the descendants of Imams, who are directly related to Muhammad. These shrines are only for the descendants of imams and they are not for imams themselves. Imamzadehs are also sayyids, though not all sayyids are considered imamzadehs. These shrine-tombs are used as centers of Shi’i devotion and pilgrimages. These shrine-tombs are also believed to have miraculous properties and the ability to heal. Many of these are located in Iraq, Medina, India and Iran.
There are many important imamzadehs. Two of these are Fātimah bint Mūsā, the sister of Imam Ali al-Ridha, the eighth Twelver Imam, and Zaynab bint Ali, daughter of Ali, considered by Shi'i Muslims to be the first Imam and by Sunni Muslims as the fourth Rashid. Imamzadehs are not traditionally women.
Many people visit the imamzadehs that are relatively close to them. There are also special ziyarat-namas (pilgrimages) for many of the imamzadehs. Some of these pilgrimages even happen annually during the certain time of year. Some of the imamzadehs are not as well kept as others. According to Reinisch an imamzadeh that he saw was mostly in ruins, though it is still important.