المعنى الاصطلاحي :

Using something wastefully, whether in terms of amount or manner.

الشرح المختصر :

"Isrāf" (extravagance) is to go beyond and exceed the sharia-determined limit, like excess in food and other matters. Islam is the religion of moderation and balance that involves neither indulgence nor negligence, neither excessiveness nor abandonment. In matters related to the worldly life and the Hereafter, a Muslim is required to perform what is allowed without increase or decrease. All the matters which Allah Almighty has commanded have two end points: excessiveness and negligence. Example of this is generosity or openhandedness, which is a moderate approach between wastefulness and miserliness and stinginess.

التعريف اللغوي المختصر :

"Isrāf": extravagance. Original meaning: exceeding the limit in everything. Opposite: "qasd" (moderation) and "i‘tidāl" (reasonability). "Musrif": extravagant. Other meanings: wastefulness, negligence, carelessness, causing damage, wasting, squandering, corruption, extremism, interruption.