The names of Angel Jibreel and Mikaa’il عليهما السلام.
*Different ways of pronunciation*
-Jibreel جبريل, with a kasra on the ج and kasra on the ر with no hamza.
-Jabreel جبريل, with a fatha in the ج and kasra on the ر with no hamza.
-Jibraa’eel جبرائيل, with a hamza after the alif. 
-Jibraa’yeel جبراييل, with two ي and no hamza. 
-Jibri’eel جبرئيل, with a hamza and ي without an alif. 
-Jibr’ill جبرئل, with a shaddah on the ل.
Abul Fath ibn Jinnaa d. 392 AH (from the imaams of Adab and Nahwu) said the origin of this name is, 

Then it was changed into the Arabic language and turned into what we have today. (Shadharaatul Dhahb, 3/140)
As for Angel Mikaa’il then it is pronounced as, 
Mikaa’yeel ميكاييل
Mikaa’eel ميكائيل 
And Mikaal ميكال.
*The meanings of these names*
Ibn Jarir collected a narration of Ibn Abbas that he said,
Jibreel means Abdullah, slave of Allah عبد الله 
And Mikaa’il means Ubaydullah, slave of Allah عبيد الله. 
*Ubayd عبيد is the اسم التصفير for the word Abd عبد. It denotes a meaning of “smaller”, “little” or any other similar  meaning*
Abdullah bin Haarith said that the word “eel” at the end of the names mean “Allah” in Hebrew. 
Abdul-Azeez bin Umayr said that Jibreel’s name amongst the angels mean servant of Allah خادم الله. (Tafsir ibn Abi Haatim 1/182)
Source: al-Itqaan by as-Suyuti.