The root ل غ و (l-gh-w) in the Quran

لَّا يُؤَاخِذُكُمُ ٱللَّهُ بِٱللَّغْوِ فِىٓ أَيْمَٰنِكُمْ وَلَٰكِن يُؤَاخِذُكُم بِمَا كَسَبَتْ قُلُوبُكُمْ وَٱللَّهُ غَفُورٌ حَلِيمٌ ۝٢٢٥

Allāh does not impose blame upon you for what is unintentional in your oaths, but He imposes blame upon you for what your hearts have earned. And Allāh is Forgiving and Forbearing.

لَا يُؤَاخِذُكُمُ ٱللَّهُ بِٱللَّغْوِ فِىٓ أَيْمَٰنِكُمْ وَلَٰكِن يُؤَاخِذُكُم بِمَا عَقَّدتُّمُ ٱلْأَيْمَٰنَ فَكَفَّٰرَتُهُۥٓ إِطْعَامُ عَشَرَةِ مَسَٰكِينَ مِنْ أَوْسَطِ مَا تُطْعِمُونَ أَهْلِيكُمْ أَوْ كِسْوَتُهُمْ أَوْ تَحْرِيرُ رَقَبَةٍ فَمَن لَّمْ يَجِدْ فَصِيَامُ ثَلَٰثَةِ أَيَّامٍ ذَٰلِكَ كَفَّٰرَةُ أَيْمَٰنِكُمْ إِذَا حَلَفْتُمْ وَٱحْفَظُوٓا۟ أَيْمَٰنَكُمْ كَذَٰلِكَ يُبَيِّنُ ٱللَّهُ لَكُمْ ءَايَٰتِهِۦ لَعَلَّكُمْ تَشْكُرُونَ ۝٨٩

Allāh will not impose blame upon you for what is meaningless in your oaths, but He will impose blame upon you for [breaking] what you intended of oaths. So its expiation is the feeding of ten needy people from the average of that which you feed your [own] families or clothing them or the freeing of a slave. But whoever cannot find [or afford it] - then a fast of three days [is required]. That is the expiation for oaths when you have sworn. But guard your oaths. Thus does Allāh make clear to you His verses [i.e., revealed law] that you may be grateful.

لَّا يَسْمَعُونَ فِيهَا لَغْوًا إِلَّا سَلَٰمًا وَلَهُمْ رِزْقُهُمْ فِيهَا بُكْرَةً وَعَشِيًّا ۝٦٢

They will not hear therein any ill speech - only [greetings of] peace - and they will have their provision therein, morning and afternoon.

وَٱلَّذِينَ هُمْ عَنِ ٱللَّغْوِ مُعْرِضُونَ ۝٣

And they who turn away from ill speech

وَٱلَّذِينَ لَا يَشْهَدُونَ ٱلزُّورَ وَإِذَا مَرُّوا۟ بِٱللَّغْوِ مَرُّوا۟ كِرَامًا ۝٧٢

And [they are] those who do not testify to falsehood, and when they pass near ill speech, they pass by with dignity.

وَإِذَا سَمِعُوا۟ ٱللَّغْوَ أَعْرَضُوا۟ عَنْهُ وَقَالُوا۟ لَنَآ أَعْمَٰلُنَا وَلَكُمْ أَعْمَٰلُكُمْ سَلَٰمٌ عَلَيْكُمْ لَا نَبْتَغِى ٱلْجَٰهِلِينَ ۝٥٥

And when they hear ill speech, they turn away from it and say, "For us are our deeds, and for you are your deeds. Peace will be upon you; we seek not the ignorant."

وَقَالَ ٱلَّذِينَ كَفَرُوا۟ لَا تَسْمَعُوا۟ لِهَٰذَا ٱلْقُرْءَانِ وَٱلْغَوْا۟ فِيهِ لَعَلَّكُمْ تَغْلِبُونَ ۝٢٦

And those who disbelieve say, "Do not listen to this Qur’ān and speak noisily during [the recitation of] it that perhaps you will overcome."

يَتَنَٰزَعُونَ فِيهَا كَأْسًا لَّا لَغْوٌ فِيهَا وَلَا تَأْثِيمٌ ۝٢٣

They will exchange with one another a cup [of wine] wherein [results] no ill speech or commission of sin.

لَا يَسْمَعُونَ فِيهَا لَغْوًا وَلَا تَأْثِيمًا ۝٢٥

They will not hear therein ill speech or commission of sin -

لَّا يَسْمَعُونَ فِيهَا لَغْوًا وَلَا كِذَّٰبًا ۝٣٥

No ill speech will they hear therein or any falsehood -

لَّا تَسْمَعُ فِيهَا لَٰغِيَةً ۝١١

Wherein they will hear no unsuitable speech.