Ibaadah:

Literally means "worship". In Islam it refers to all those acts of worship with which one renders worship to Allah Ta'ala.

Imam:

Literally means "leader". In kitaabus salaat it refers to the leader of the congregation for salaat.

Imaamat:

Refers to the act of being an imam or the entire institution of imaamate which deals with the appointment, rules, regulations, etc. which are related to the imam.

Iqaamah:

Refers to the second call to salaat in a musjid indicating the imminent beginning of the salaat with congregation. For further details, refer to the chapter on adhaan and iqaamah.

Iqtidaa:

Refers to the act of following the imam in salaat.

Ishaarah:

Literally means "gesture". In kitaabus salaat it refers to the offering of salaat through gestures and signals for the person who is unable to offer his salaat in the normal stipulated manner due to sickness or physical handicap.

Istighfaar:

The seeking of forgiveness from Allah Ta'ala.

Istikhaarah:

The seeking of good from Allah Ta'ala. For further details, refer to the chapter on salaatul istikhaarah.

Istinja:

Cleansing of one's private parts after having relieved oneself. This is irrespective of whether this cleansing is done with water or lumps of sand.

I'tikaaf:

Literally means "to live in seclusion". In Islam, it generally refers to the act of secluding oneself in the musjid in the month of Ramadaan.