"مو به تن ادم سیخ شدن" .واکنش بدن وقتی یک چیز غیرمترقبه می شنوی, می بینی یا حس میکنی, یا وقتی یهو احساس سرما می کنی The reaction of the body when imposed in the cold weather (with improper cloths) or when you sense (hear, see, touch, feel) something or someone unexpectedly/shockingly.

Simple - pluck feathers from a goose (or chicken) it is how skin looks like when cold sometimes

pimples on your skin when you're cold for example

Hey! Goose bump means something similar to chill, creeps. You now? Like when your arm hair are up. See this picture http://www.beliefnet.com/columnists//dreamgates/files/2012/02/Goose-bumps-image-1.jpg

Actually I checked Longman dictionary, but I couldn't find this word there. Anyway, Thank you Lee.