"Ihsār": gathering, detention, prevention. Examples of "ihsār" include such cases when a person is prevented by illness or travel from doing something, and when a pilgrim is prevented by illness or some other cause from completing the rituals of Hajj.
"Fawāt": missing something by not doing it on time. Original meaning: the opposite of catching up with something and reaching it. Other meanings: lapsing, ending.
Completing the rites of Hajj and ‘Umrah after initiating them.