• أَوْسَط
• أَوْسَطهُمْ
• وَسَط
• وَسَطْنَ
• وُسْطَىٰ

Appears 5 times in the Quran.

1. 2:143 وَكَذَٰلِكَ جَعَلْنَٰكُمْ أُمَّةً وَسَطًا لِّتَكُونُوا۟ شُهَدَآءَ عَلَى ٱلنَّاسِ وَيَكُونَ ٱلرَّسُولُ عَلَيْكُمْ شَهِيدًا وَمَا جَعَلْنَا ٱلْقِبْلَةَ ٱلَّتِى كُنتَ عَلَيْهَآ إِلَّا لِنَعْلَمَ مَن يَتَّبِعُ ٱلرَّسُولَ مِمَّن يَنقَلِبُ عَلَىٰ عَقِبَيْهِ وَإِن كَانَتْ لَكَبِيرَةً إِلَّا عَلَى ٱلَّذِينَ هَدَى ٱللَّهُ وَمَا كَانَ ٱللَّهُ لِيُضِيعَ إِيمَٰنَكُمْ إِنَّ ٱللَّهَ بِٱلنَّاسِ لَرَءُوفٌ رَّحِيمٌ

   And thus We have made you a medium (just) nation that you may be the bearers of witness to the people and (that) the Messenger may be a bearer of witness to you; and We did not make that which you would have to be the qiblah but that We might distinguish him who follows the Messenger from him who turns back upon his heels, and this was surely hard except for those whom Allah has guided aright; and Allah was not going to make your faith to be fruitless; most surely Allah is Affectionate, Merciful to the people.
   

2. 2:238 حَٰفِظُوا۟ عَلَى ٱلصَّلَوَٰتِ وَٱلصَّلَوٰةِ ٱلْوُسْطَىٰ وَقُومُوا۟ لِلَّهِ قَٰنِتِينَ

   Attend constantly to prayers and to the middle prayer and stand up truly obedient to Allah.
   

3. 5:89 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

   Allah does not call you to account for what is vain in your oaths, but He calls you to account for the making of deliberate oaths; so its expiation is the feeding of ten poor men out of the middling (food) you feed your families with, or their clothing, or the freeing of a neck; but whosoever cannot find (means) then fasting for three days; this is the expiation of your oaths when you swear; and guard your oaths. Thus does Allah make clear to you His communications, that you may be Fateful.
   

4. 68:28 قَالَ أَوْسَطُهُمْ أَلَمْ أَقُل لَّكُمْ لَوْلَا تُسَبِّحُونَ

   The best of them said: Did I not say to you, Why do you not glorify (Allah)?
   

5. 100:5 فَوَسَطْنَ بِهِۦ جَمْعًا

   Then rush thereby upon an assembly: