Integral (لازمی) means 'necessary' (ضروری) to make a whole complete; fundamental or 'essential' (بنیادی).

To instigate (اکسانا) means to bring about or initiate an action or event, often a bad one. 'Prompt' (آمادہ کرنا) or to 'cause' is the best synonym.

Instantaneous (فوری) means occurring or done in an instant. 'Immediate' (بلا تاخیر) is the most direct synonym.

Insensate (بے حس) means lacking physical sensation or lacking compassion. 'Unfeeling' (سنگدل) is a direct synonym. 'Ruthless' (بے رحم) is a related concept but 'unfeeling' is more precise.

Insatiable (ناقابل تسکین) describes an appetite or desire that is impossible to satisfy. 'Greedy' (لالچی) is a strong synonym, implying an endless desire for more.

Insanity (پاگل پن) is the state of being seriously mentally ill. 'Madness' (دیوانگی) is a direct synonym. 'Clarity' (وضاحت) and 'Wisdom' (عقل) are antonyms.

Inquisitive (متجسس) means having or showing a strong interest in learning things; 'curious' (پوچھ گچھ کرنے والا).

An inquest (تحقیقات) is a judicial inquiry or 'investigation' (تفتیش) to ascertain the facts relating to an incident, most commonly a sudden death.

To inhabit (رہنا) a place means 'to live' (آباد ہونا) or dwell in it as a person, animal, or group.

Ingenuous (سادہ لوح) describes a person who is innocent, simple, and 'naive' (ناتجربہ کار). 'Cunning' (مکار) and 'Sophisticated' (تجربہ کار) are antonyms. (Do not confuse with 'ingenious', which means clever).