Meaning of Curse

Lanat or Laa'an, the word العن literally means in English 'anathematize' (.ie: a ban or curse solemnly pronounced by ecclesiastical authority and accompanied by excommunication; this is the closest meaning in English) or more commonly 'curse'.

Curse from Shia Point of View

Cursing AbuBakr And Umar:-

1) Hanan Ibn Sadir narrated:

I asked Imam al-Baqir (AS) about these two (That is Umar and AbuBakr). He(AS) replied: "O Aba al-Fadhl! Do not ask me about them for, by Allah, non among us (Ahlul-Bayt) would die except that he is displeased with those two. No day passes to us except that we are angry with them. Indeed, they oppressed

Curse from Sunni Point of View

1) Janabe Fatema Zehra(SA) was angry with Abubakr and used to curse him and did not talk to him till her death .

Ref :    Sahih Bukhari Kitab Magazi Bab Guzwwe Khaiber V 3  Pg 55.

2) The Proof of Sending Curses(Lanat) on Yazid!

The Proof of sending Lanat upon Yazid is derived from this (ayah), as was mentioned by Al-Barzanji  in his Al-Ashaat and Imam Haythami I in As-Sawaiq from Imam Ahmed  that his son Abdullah asked him about sending Lanah on Yazid, and how sending Lanah upon him is mentioned in the book of Allah (i.e. Quran).

Curse in Holy Quran

Holy Quran and Lanat (Curse)

Quranic Verses can be divided into four parts.

1. Curse on Iblis.

‘And surely on you is curse until the Day of Judgment.’                                       
(Surah Hijr, 15:35)

‘And surely My curse is on you until the Day of Judgment.’                              
 (Surah Suad, 38:78)

Allah has cursed Iblis. (i.e. He has made him far from His Mercy.) When Iblis was cursed, he said to Allah, ‘I will certainly have a special share from Your servants.’