Descriptions of Atticus's physical appearance are minimal in the story. The chief focus throughout is on his sterling inner qualities. However, we do know that he is 'nearly fifty' and to the young Scout's way of thinking, this makes him 'feeble'. The reference to him wearing glasses and being nearly blind in his left eye, as quoted in the previous answer, is probably the most extended physical description we get of him. Incidentally, his observation about 'left eyes' being 'the tribal curse of the Finches' is an amusing twist on his sister Aunt Alexandra's obsession with heredity. Aunt Alexandra is always going on about the genteel and noble qualities of the Finch family from generations back, but that doesn't interest Atticus.
There is also a reference to Atticus's size, when at one point Scout remarks that
For a big man, Atticus could get up and down from a chair faster than anyone I ever knew.
This is when Scout has just answered back to her aunt and Atticus swiftly intervenes to make her apologize.
A quote is any line from the book. The words spoken by a character is dialogue.
The description is actually in chapter 10, but we have to keep in mind that he is described by Scout who is very young and very unreliable. "Atticus was feeble" "he wore glasses. He was nearly blind in his left eye, and said left eyes were the tribal curse of the Finches."
As an attorney, Atticus wears a suit and tie every day to work. He is also described as having glasses, as pointed out at different times when he adjusts them to look at Scout; and in the courtroom scene, he wore suspenders and an inner coat vest. In chapter 10, though, a more detailed description is given as Scout calls him feeble and fifty. Scout calls him feeble because he doesn't play football, hunt, fish, drink or smoke like the other fathers that she sees in town. The glasses also drop him on the awesome scale in Scout's book. Then, the fact that he is fifty, and older than all of the other children's parents, makes him seem like a grandpa rather than a father. Scout describes him as follows:
"When Jem and I asked him why he was so old, he said he got started late, which we felt reflected upon his abilities and manliness. He was much older than the parents of our school contemporaries, and there was nothing Jem or I could say about him when our classmates said, 'My father--'" (89).
Consequently, Scout and Jem think their dad is old, fragile, and boring. They don't think there is anything unique about him to brag to their school friends about.