لَعَلَّ

A word in the Arabic language will either be 1) a verb or 2) a noun or 3) a particle – لَعَلَّ is a particle

إِنَّ وَأَخَوَاتُهَاحَرْفُ مُشَبِّهِ بِالْفِعْلِحَرْفُ نَصْبٍلَعَلَّIt is hoped thatحَرْفٌحَرْفٌ لِلتَّمَنَّى
Inna and her sistersParticle resembling a verbAccusative particleRootIt may be thatParticleParticle of wishing