Literally, the Masjid means the place of prostration. Technically, it means any place prepared so that Muslims may offer the five obligatory Prayers in congregation in it. It may be used in a broader sense. In this case, it means any place in a person's house where they may offer Nafilah (supererogatory) Prayers or obligatory Prayers in case they (for men) have a legal excuse that prevents them from going to the Masjid in which the congregational prayer is performed. In this regard, there is a Hadith
Al-Bukhari and others
on the authority of
Jabir who said: The Prophet (peace be upon him) said:
I have been endowed with five (things) which were not granted to anyone before me (and these are): Allah made me victorious by awe (by His frightening my enemies) for a distance of one month’s journey, and the earth has been made for me (and for my followers) a place for praying and a Tahur (purifier); therefore, any of my followers can pray whenever the time of any prayer is due...