"Gall" can also mean "a spirit to resent injury or insult." In other words, taking offense too easily at someone's words or actions.
"Atomies" are very tiny horses that pull Queen Mab's chariot.
"Ward" can also mean guard or preservation (as Linda mentioned above - someone who has a guardian). In addition, "ward" is a fencing guard; a prison-cell; the bolts or locks of a door; and a district of a town. So you will have to figure out which definition fits the best based on the context.
Please be sure to include act and scene numbers when you ask questions like this. It really helps the editors to find the specific passages and then answer your questions more thoroughly. Here is a link to a very good on-line Shakespearean dictionary which you might find useful:
Good luck! :)
These are words we don't use very often anymore. If you want some hints on how to make reading Shakespeare easier, read this week's blog on play production. I've pasted the link below.
Also, eNotes has a side-by-side versions of the play in Elizabethan English and in modern text. I've pasted that link for you too.
Now, let me "translate" these words for you.
gall: stomach acids, like heartburn
teen: Do you mean tween? If so, it's a poetic way of saying "between"
dug: a very old way of referring to a woman's breast, especially if she's old
atomies: I have no idea what Shakespeare means by these. Since they are pulling Queen Mab's coach, I can guess that they are some sort of very small faery creature.
ward: a young person who has a guardian; think of our expression "ward of the court"
I hope this helps.