Thank you for your attempt to edit my post better, and I appreciate every edit you make. However please keep in mind that I intentionally use lagrangian, not Lagrangian.
I know that Lagrangian is widely accepted and if I write it differently, you will find something not right, and you have the itch to fix it. When you read the words, you are not spelling every character it has, but recognizing it as a whole gesture. By remember the whole gesture, your speed of reading will be enhanced, therefore your brain saves the energy for other task, such as truly understanding the text. That's why misspelling words are irritated because it interrupts your reading flows. Seeing it lowercased while you expecting it uppercased makes you feel the same.
However, I have my own rationale. Google is a company name, a proper noun, but google is a verb; Fermi is a person name, a proper noun, but fermion is a noun. I think writing lagrangian in lowercase is not wrong; In his book, Quantum Mechanics and Path Integral, Feynmann also wrote lagrangian in lowercase.
I'm not saying that you are absolutely wrong, nor I'm absolutely right. There is no wrong or right in languages, just majority and minority. Therefore I don't mind if seeing Lagrangian. However, please let me write it in the way I feel right. Thank you for your understanding and sorry if this makes any inconvenience.
I don't mind if you downvote this. I preset this line below so that every time I foresee that someone will uppercase lagrangian, hamiltonian, etc, all I need is just copy this line into my post.
<!-NOTE: I intentionally write "lagrangian" in lowercase. See http://meta.physics.stackexchange.com/q/6257/41634->