Impossible

Impossible, The word 'impossible' has not been used here in the sense of physical or literal impossibility. The performance of an act may not be literally impossible but it may be impracticable and useless from the point of view of the object and purpose which the parties had in view; and if an untoward event or change of circumstances totally upsets the very foundation upon which the parties rested their bargain, it can very well be said that the promisor finds it impossible to do the act which he promised to do, Satyabrata Ghose v. Mugneeram Bangur, AIR 1954 SC 44 (46). (Contract Act, 1872, s. 56)

Means in the language of everyday life a thing is impossible when according to the ordinary course of human events, no expectation can be entertained that it will happen, Shephard v. Kottgen, (1877) 47 LJQB 67.