How do i add two lists' elements into one list?

For example, I have a list like this:

list1 = ['good', 'bad', 'tall', 'big']

list2 = ['boy', 'girl', 'guy', 'man']

and I want to make a list like this:

list3 = ['goodboy', 'badgirl', 'tallguy', 'bigman']

I tried something like these:

list3=[]
list3 = list1 + list2

but this would only contain the value of list1

So I used for :

list3 = []
for a in list1:
 for b in list2:
  c = a + b
  list3.append(c)

but it would result in too many lists(in this case, 4*4 = 16 of them)