I. re ‧ tard 1 /rɪˈtɑːd $ -ɑːrd/ BrE AmE verb [transitive]
[ Date: 1400-1500 ; Language: Latin ; Origin: retardare , from tardus 'slow' ]
formal to delay the development of something, or to make something happen more slowly than expected SYN slow down :
Cold weather retards the growth of many plants.
II. re ‧ tard 2 /ˈriːtɑːd $ -ɑːrd/ BrE AmE noun [countable]
spoken not polite an offensive word for a stupid person