* Hazrat Abdullah (رحمت اللّہ ) said that meaning of Imaan is the name of asserting something.
* Hazrat Zahri (رحمت اللّہ ) said that Imaan signifies action (amal).
* Rabiya bin Anas (رحمت اللّہ ) said that Imaan means to fear.
Thus combining all these, we get the meaning as follows:
Believer (Momin) is one who brings Imaan through tongue, heart, action & also believes the unseen.
A believer is also bound to bring Imaan on Allah (عزوجل), His books, His doctrines. He is also bound to express his belief & act according to the same.
According to Abu Al Aaliya (رحمت اللّہ ) Imaan of a Believer is to put belief on Allah عزوجل, His angels, His books, His messengers, the day of Judgement (Qayamah), Heaven, Hell, Meeting with Allah عزوجل, Life after death etc.
Thus Imaan is the part & parcel of a Believer (Momin). Our identity is Imaan. Let us make full efforts to keep it intact.
Muhammad صل اللّہ علیہ وسلّم once said to his Sahabas that save your Imaan with your teeth!
Let us act in accordance with this Hadees.
Any mistake, on my part, if found, may please be forgiven.