to boast = se vanter (=to brag) « Stop boasting! »
to boast about sth = se vanter de qch. « Carol boasted about her costume. »
to boast of/that = se vanter de « He boasted of being involved in the arms theft. » « He boasted that he was someone great. »
vantardise « This isn't meant as a boast » « her boast of being a great lover. »