[بسم] التَبَسُّمُ: دون الضحك. يقال: بَسَمَ بالفتح يبسِمُ بَسْماً فهو باسمٌ، وابْتَسَمَ وتَبَسَّمَ. والمَبْسِمُ: الثغر، مثال المجلس من جلس يجلس. ورجلٌ مِبسامٌ وبَسَّامٌ: كثير التبسُّم.
Volunteers needed (having reasonably advanced knowledge of Arabic, and relatively good English): There are 20-40 dictionaries that can be added to The Arabic Lexicon once the digital versions are reviewed and any necessary corrections carried out (sometimes this can be done in a few hours). If you're interested, please email me at this address: contact@hawramani.com.