(س) حَمِدَ يَحْمَدُ حَمْدًاḥamida yaḥmadu ḥamdan: to praise someone for both his excellence and his beneficence. The lexicographers have drawn a distinction: مَدْحmadḥ is for excellence alone, even if it is not voluntary; شُكْرshukr is for beneficence alone; and حَمْدḥamd embraces both — which is why the Quran opens with «الْحَمْدُ لِلّٰهِal-ḥamd lillāhi». This root occurs 63 times in the Quran. ﴿اَلْحَمْدُ لِلّٰهِ رَبِّ الْعٰلَمِيْنَ﴾ (Al-Fātiḥah 1:2)
حَمِيْدḥamīd (فَعِيْلfaʿīl): one who is ever praiseworthy. ﴿اِنَّهُۥ حَمِيْدٌ مَّجِيْدٌ﴾ (Hūd 11:73)
حَامِدḥāmid pl. حٰمِدُوْنḥāmidūn: one who praises. ﴿اَلتَّآئِبُوْنَ الْعٰبِدُوْنَ الْحٰمِدُوْنَ﴾ (At-Tawbah 9:112)
مَحْمُوْدmaḥmūd (passive participle, ism mafʿūl): one who is praised. ﴿عَسٰٓى اَنْ يَّبْعَثَكَ رَبُّكَ مَقَامًا مَّحْمُوْدًا﴾ (Al-Isrāʾ 17:79)
Form II (tafʿīl) حَمَّدَ يُحَمِّدُ تَحْمِيْدًاḥammada yuḥammidu taḥmīdan: to praise repeatedly; مُحَمَّدmuḥammad (passive participle, ism mafʿūl): one who is praised again and again. ﴿مُحَمَّدٌ رَّسُوْلُ اللّٰهِ﴾ (Al-Fatḥ 48:29)
اَحْمَدُaḥmadu (elative, ism tafḍīl): the most praising / the most praiseworthy. ﴿اسْمُهُۥٓ اَحْمَدُ﴾ (Aṣ-Ṣaff 61:6)