I'm wondering if the
rud portion of
Rudra is etymologically connected to the
rut portion of
Marut. My understanding is that
rudra literally means "howl" or "roar" and
marút means "wind," "air," or "breath." So, can these words be broken into etymological parts?
One day, Diti was very tired and fell down asleep. Her hair was untied and her head had stooped down while she was sleeping, just opposite to the instructions Kashyapa had given to her. Finding the moment opportune, Indra entered into Diti's womb and cut the foetus into seven pieces with his Vajra. The seven fragments of foetus instantaneously got transformed into seven infants and started wailing. Indra became furious and once again he attacked them with his vajra and severed them into seven pieces each. But to Indra's sheer amazement, there were 49 infants, all wailing loudly. He tried to stop them from crying by shouting 'Marud' (don't cry), but to no avail.
Indra realized that the infants had attained immortality on account of the 'Pournamasi Vrata', which Diti had devoutly observed during the course of her penance. Indra named the infants as Marudganas and blessed them. He then begged for Diti's forgiveness and took her along with the Marudganas to heaven. The Marudganas, despite being born in the clans of demons, never associated with them and hence were revered even by the deities.
One of the eight sons of Brahma started wailing after being created from his (Brahma) body. Brahma asked him as to why he was crying. The crying child requested Brahma to give him a name. Brahma named him as Rudra since he was wailing at the time of his birth.
Note: Here it's Rudra and NOT Shiva. ( See the difference in Are Lord Shiva and Lord Shankar two different deities? ).
So root verb for both the words is रुद् (rud) means cry.
Ma + rud means don't cry.
Indra means "possessing drops of rain" from Sanskrit इन्दु (indu) meaning "a drop" and र (ra) meaning "acquiring, possessing".
It is like this in Sanskrit --
रुद् means cry/weep.
मरुत् means वायु.
There is a story in 'Shrimat Bhagwat Mahapurana'.
When Diti, the mother of the daityas (demons), was pregnant and expecting a very powerful son as per the blessing of her husband Kaśyapa, that time Indra, the king of gods, stealthily broken the foetus into 49 parts. These ‘babies’ started weeping. At the request of their mother Diti, Indra granted them protection and godhood. He told them not to weep (मा रुद ). Hence it is मरुद्.
He made them the controllers of wind. Hence comes मरुत्.
Marudgaṇa is a group of Maruts.